[ponyakr]

Are there ANY other 350P blocks to avoid, besides the
500810 1975-1977 350P blocks?

Also,
My plan is to build a mild 350P (375-395-ish ponies) street/auto x motor,
and set it up with a mild twin turbo system (low boost around 10-ish psi or so)
with moderate sized turbos to maintain my low-mid range grunt (and blow-thru carb etc of course)
Can a poncho 350, handle boost well?
Anything to watch out for, or to avoid?

There are no other weak blocks to avoid that I know of. Just need to find one that has thick enuff cylinder walls to be safe with a .060 overbore. The thicker the better.

But, the power level you are talking about will require some better parts that I haven't got around to discussing yet. Now, when it comes to turbos, I'll admit, I know absolutely nothing about them. I do know that the Butler twin turbo drag car makes some awesome power. So in order for a 350P to make power passed 600hp or so, will require some high end parts. I figure you can attain somewhere between 550 and 600hp with one of the Butler's forged crank 4.25 stroker assemblies. You mentioned low to mid range grunt. This 4.25 stroker may give you all the grunt you want !

http://www.jbp-ponti...es.html#407_413

Then you'll need a roller cam set-up, and some ported alum heads, set up specifically for the small bore block, turbo app. Then, with that much power you'll need aftermarket 4-bolt caps, to keep from blowing the bottom end out of it. You'll probably need lifter bore braces, and you'll definitely need to run Cometic head gaskets.

Stock block motors have made close to 800hp and lived. My neighbor built a 400 block stroker that dynoed @ 755 hp.

He has it in his '69 street GTO !

He is also in on the 1200 + hp RA5 head build. If you got enuff $$, the Butlers can build it to the max. But this guy I'm talkin about can build it for a reasonable price. And he has a 350 block with 8 sleeves in it that he was going to use for another high end build, but didn't. If you are REALLY serious about this build, I can put you in touch with him.

 

[ponyakr]

OK, with what we've learned so far, here's how I would build a basic low buck 350. This is not a complete parts list, just the basics.

(1) '70-'74 block with all 5 motor mount holes on each side, sonic tested for safe .060 overbore.

(2) One of the small valve 72cc heads, with the previously discussed parts and machine work.

(3) Sealed power #357P60 cast pistons.

http://www.summitracing.com/parts/slp-357p60/overview/make/pontiac

(4) Either the 5140 forged rods or preferably the Tomahawk rods we discussed.

http://www.competitionproducts.com/5140-I-Beam-Rods-Pontiac-6625-Press-Pin/productinfo/4556/#.U1Ny01VdVZ5

http://forums.performanceyears.com/forums/showpost.php?p=5050633&postcount=1

http://forums.performanceyears.com/forums/showpost.php?p=5137912&postcount=18

(5) .027 thick Cometic head gaskets with a bore size of 3.975

http://www.spottsperformance.com/cometic%20head%20gaskets

(6) Cam:

1st choice: Melling SPC-7

http://www.ebay.com/itm/MELLING-SPC-7-Engine-Camshaft-Stock-/321322992470?_trksid=p2054897.l5659

2nd choice: Summit 2801

http://www.summitracing.com/parts/sum-2801/overview/

(7) Rhoads lifters.

http://www.summitracing.com/parts/rhl-9518/overview/make/pontiac

(8) Melling M54DS oil pump with .050-.060 shim under pressure spring.

http://www.summitracing.com/parts/mel-m54ds/overview/

(9) One piece BOP seal.

http://www.bopengineering.com/beltdrive_acc_topend.shtml

(10) New Powerbond balancer.

http://www.ebay.com/itm/Pontiac-350-400-455-Powerbond-Harmonic-Balancer-PB1056N-/310775103209?_trksid=p2054897.l5658

(11) Good used Performer #2156 or stock early iron 4-barrel Q-jet intake.

(12) Good PROPERLY REBUILT Q-jet-- '68-'70 Pontiac or '68-72 Buick--NOT the '71 up Pontiac with the big smokestack vent.

http://www.everyday-performance.com/quadrajet_carburetors.htm#!/~/product/category=578011&id=33759629

http://www.smicarburetor.com/products/sfID1/28/sfID2/9/sfID3/100/productID/841

http://www.carburetion.com/Rebuilt/datainfo.asp?Part_Nbr=4-244&Application=Pontiac&Year=68%2069%2070

 

[ponyakr]

Now I'm going to estimate the cost of the basic 350 motor I described to be between $3000 & $4000 , depending on machine shop costs, and the cost of the used parts needed for the build. This should be slightly lower than a similar 400 build, because you should be able to buy one of the '68,'69, or '70 350 2-barrel motors, real cheap. There is just no demand for 'em, and they came in lots of Birds, Tempests & Lemans . Most long time Pontiac guys will have one or more of these layin around their shop. Some will sell cheap and be glad to get rid of 'em.

Most guys who buy these old cars to restore, or even drivers and cars that are already restored, will pull the 350 2bl motor and replace it with a 400 or 455. Some of these are in good running condition. Others may just be good cores for rebuilds. In most places, if you check around, you can find a usable 350 2-bl real cheap.

 

[ponyakr]

I decided to check on rebuilt 350P engines. There are some real cheap engines with warranties. Some give you a choice of heads. The numbers I've seen are 94, 4x, 5c, & 6x. But without taking some off, these will produce less than 8:1 comp. They start at around $2000 and go up to $3500 for a Tuff Dog with , balance assembly, and a new Performer intake. Some of these say they will custom build, with different options. So I suppose it would depend on what block and head cores they have in stock as to what they could build.

Anyhow, for the guys who can't do any of his own engine assembly, this may be a good alternative. The main problem I see with these cheap engines is the low comp heads. An 8:1 350P just can't make much power. I'll post a few links. For more you can Google something like: remanufactured Pontiac 350 engine.

http://www.amazon.com/PROFessional-Powertrain-DP28-Complete-Remanufactured/dp/B007CXKOJ0

http://www.ebay.com/itm/PONTIAC-350-5-7L-Engine-70-71-Rebuilt-Block-V8-/250415231440

http://www.ebay.com/itm/PONTIAC-350-CRATE-ENGINE-BY-TUFF-DAWG-ENGINES-/161273288995

This one claims to be a '68-'69 with possibly #17 or #18 heads ? 7 year warranty. But the price is as of '09, so is this site even current ? And do they have these cores in stock ? If you ordered one of these, what would you actually get ? I can't answer any of these questions.

http://www.autoguide.net/apf/pontiac-car_engines/pon_350lb.html

This site says that any upgrade from mild to wild is available on any Pontiac motor they sell. And they show a '70 350P with either #11 or #47 heads, If they have these cores, this has potential.

http://remanufactured.com/Pontiac_Engines.htm

http://www.rebuiltautoengines.com/pontiac-V8_5.7_350-pon_350lb-engine.html

http://www.powertrainproducts.net/PONTIAC-350-5-7-V8-73-77-COMP-ENGINE-p/1890.htm

http://www.eddiesperformance.com/pontiac-crate-engine.htm

http://rebuilt.net/Pontiac_Engines.htm

 

[ponyakr]

Now, we'll start lookin at some of the possible upgrades or mods we can do, using the stock crank. The 1st one that comes to mind is to offset grind the crank for a bit more stroke. Summit lists .040, .050. and even .060 undersize rod bearings for the Pontiac rod journals. If the .050 is actually available, that means that it is possible to increase the stroke by at least .020. Why do that ? Because most factory Pontiac motors have the top of the piston at least .020 or more in the hole. And most engine builders recommend zero deck height for high performance builds. So by increasing the stroke .020, we would not only have slightly more cubic inches, but also near zero deck height.

And any increase in the cost of offset grinding, would be at least partially offset by not having to deck the block for zero deck height.

By grinding the journals down to BBC size we can switch to the 6.635 BBC H-beam rod. Now what would be the advantage of this change ? The 1st obvious advantage is the extra strength of the Eagle H-beam rod. I think this length rod is made for the 502 BBC motor. Now since most 350 pistons are designed to be just over .020 in the hole (below the deck), this rod will move the piston up .010. Also, since the BBC rod journal is smaller than the Pontiac journal, the stroke can be offset slightly when ground to the BBC size. The ideal amount would be about .010 longer stroke. With that amount added to the extra .010 length of the rod, it will put the top of the piston real close to the deck. Many engine builders say that zero deck height is best for any performance build. So the combo of longer rod and longer stroke will get us close to this zero deck height, without cutting any off the deck.

Now the crank will have to be turned down at least .010 anyhow, so it shouldn't cost much extra to offset grind it to the standard BBC size. Pontiac rod journals are 2.25". BBC journals are 2.20". So that means that the Pontiac journal will have to be turned down .050 to get it to the BBC size. Now theoretically you could increase the stroke of the crank by 1 / 2 of that .050, or .025 when offset grinding it the maximum. But crank grinders use the figure of 80% as the max amount of stroke increase you can get . In other words, 80% of .025, which is .020, is all the stroke change that can be achieved with a 2.20 journal. This allows for slight wear of the journal surfaces, and the amount that will be removed with final polishing of the journal. So, That means that if the crank has not been turned before, and there is no extreme wear on the journals, it is possible to offset grind the crank and increase the stroke by .020. Now if you need just a bit more, you can grind the journal down to what ever under size bearings are available for the BBC. Summit has .040, .050, and even .060 undersize BBC bearings. So that means you could turn the Pontiac journal down at least .100 and increase the stroke by .040, with offset grinding. How much would this cost ? I don't know. It would probably depend on the crank grinder and how much high performance grinding they do.

Is your brain scrambled yet ? Back in the old days, if you were playing a pinball machine and raised it up any or slapped it too hard on the side, it would stop the game and read "Tilt--Game Over" !

 

[ponyakr]

Now, since I can find no reasonably priced forged piston for a 350P, I'll submit this possibility. Run a 6.535 BBC rod and a forged 318 Mopar piston.

The rod:

This is a popular BBC length rod. There are Chinese units from cheap 5140's up to Scat H-beams for over $400.

http://www.ebay.com/itm/I-Beam-6-535-2-200-990-Bronze-Bush-5140-Connecting-Rods-Suits-Chevy-BBC-454-/171245420832?pt=Motors_Car_Truck_Parts_Accessories&hash=item27df05c120&vxp=mtr

http://www.ebay.com/itm/H-Beam-6-535-2-200-990-Bronze-Bush-4340-Connecting-Rods-Suits-Chevy-BBC-454-/171245415729?pt=Motors_Car_Truck_Parts_Accessories&hash=item27df05ad31&vxp=mtr

http://www.ebay.com/itm/I-Beam-Race-6-535-2-200-990-Bronze-Bush-4340-Connecting-Rods-Chevy-BBC-454-/181327618992?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a37f7e3b0&vxp=mtr

http://www.ebay.com/itm/Dart-eBay-Only-BB-Chevy-5140-Steel-I-Beam-Conn-Rods-6-535-750hp-Max-/380818104459?pt=Motors_Car_Truck_Parts_Accessories&hash=item58aa87208b&vxp=mtr

http://www.ebay.com/itm/BBC-Chevy-454-Forged-Steel-6-535-Rods-H-Beam-ARP-Bolts-396-427-Big-Block-/330816045712?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d062c4290&vxp=mtr

http://www.nolimitmotorsport.com/prod/EGL-CRS65353D

http://thmotorsports.com/eagle/eagle_connecting_rod_set_hbeam/crs65353d/i-329459.aspx

The pistons:

http://www.summitracing.com/parts/wis-pt083a3/overview/make/dodge

http://www.campbellenterprises.com/Chrysler-Dodge-Mopar-Pistons-318-Flat-Top-Pistons-ic84430-Icon-Pistons_3216.prt

http://www.cnc-motorsports.com/icon-ic844-030-forged-flat-top-pistons-3-940-bore.html

We'll discuss how to put all this together in the next post.

 

[ponyakr]

OK, to mate these rods and pistons, you'll either have to bush the rods for the .984 Mopar pins, or fit the pistons with .990 BBC pins. Either will work. So I suppose it just depends on which is cheaper to do. I reckin only the machine shops will know that.

Then, of course, you'll need to have the rod journals turned down to BBC size, which is 2.20. Now if you grind it to maintain the stock 3.75 stroke, the Wiseco piston will be .010 higher in the hole than a stock Pontiac piston. And how did I arrive at that conclusion ? Well, the BBC 6.535 rod is .090 shorter than the Pontiac 6.625 rod. But the pin height of the Wiseco 318 piston is .100 higher than pin height of the Sealed Power 357P piston. 1.80 minus 1.70 = .100. So .100 higher minus .090 shorter = .010 higher.

Now if you use the Icon piston, the top of it will be .010 higher in the cylinder than the Wiseco piston, because it's pin height is 1.810. From what I've read, Pontiac put the top of most of their pistons about .020 in the hole. So, if the block you use has never had any of the deck cut off of it, then the top of the Icon piston should be close to the deck. And the Wiseco will be .010 lower. Of course, this can be changed by offset grinding the crank to increase the stroke slightly. So, even tho the Wiseco price I found was a little lower than the Icon's. The Icons may be cheaper overall, depending on how much the crank grinder charges for the offset grind.

The only other problems I can see with using the 318 pistons is possibly needing to modify the valve reliefs slightly. if you run the small valve heads and a low lift cam, they may not need any changes at all. This combo should be quite safe to 7000rpm, if you wanna take it that high.

I called Ohio Crank to see if they can bush their BBC rods for .984 pins. He said he would have to ask somebody and would call me back, but never did. I reckin he thought I was crazy. I also called BRC to see if they can sell a 350P piston cheaper than Ross. But they were closed. If any of you guys know of a source for some 350P forged pistons cheaper than Ross, please post that info here. With pistons, pins, pin fit and freight, the Ross pistons will cost nearly $800.

http://www.jbp-ponti...ns/pistons.html

 

[ponyakr]

OK, lets assume you get a stock stroke shortblock built. What cam are you going to run ? Well, the small cube 350P can't handle the big cams like the 455's can. For me, here's a good rule of thumb. For the 455, with 9.25 or higher CR, I consider the RA4 spec cam with Rhoads lifters a good minimum baseline cam. It will idle smooth and have good off idle throttle response and gobs of low rpm torque. However, if you got a 350P I'd consider the RA4 and Rhoads absolute max, even for bracket racing. And you would need either a 4-speed or a stall converter and decent gears, at least 3.73's. No, as much as I like the RA4 spec cam, I'll have to recommend something smaller for a street 350P.

If you are going to run the low numbered gears, like 2.41, 2.56, 2.73, 3.08, with an auto tranny and stock converter, then you need to stay with a really small cam. Running this set-up likely means you are gonna do lots of highway cruisin , and will want low rpm and good gas mileage. Now, I'm gonna assume that you'll be running 9.5 CR or lower so that you can run 91-93 octane Pump gas. So, from 8.5 -9.5 Cr an 068 spec grind with Rhoads lifters is about the max I'd recommend. Tho. even smaller would probably get better mileage. I'll post the links to some of these small cams of different brands. This is not an exhaustive list, by any means. Most of these links will be to the Summit site, because they usually list all the cam specs. However, Ebay usually has a better price on most cams, but not always. I always Google each cam and search for the lowest shipped price. Sometimes Summit will match a better price.

http://www.summitracing.com/parts/mel-spc-4/overview/make/pontiac

http://www.summitracing.com/parts/sum-2800/overview/make/pontiac

http://www.cnc-motorsports.com/camshafts-lifters/crower/crower-60240-hydraulic-flat-tappet-camshaft.html

http://www.summitracing.com/parts/hrs-417591-15/overview/make/pontiac

http://www.summitracing.com/parts/sum-2801/overview/make/pontiac

Here's a link which has lots of Pontiac cam specs. You can see some of the other cams with similar specs to these I've listed. For CR above 9:1, the XE & Voodoo steep ramp style cams are probably not the best ticket, as they may increase cylinder pressure too much.

http://ronspontiacpage.com/reference-pages/aftermarketcamspecs.htm

 

[ponyakr]

OK, let's assume that everything is the same as in the last post except that you decided to keep your 6x or similar low comp heads. That means that even with some head shaving, you're still at or below 8:1 CR. I think the factory HP rating was well below 200, with around 7.6 CR. These motors need all the help they can get !

This is where the steep ramp cams, like the XE and Voodoo series, really shine. They increase cylinder pressure.

So, after lookin thru the cam specs, here are some of the smaller cams that might work in a low comp, highway geared 350P app The last two may be too big for stock converter, 2.41, 2.56 gear apps. And borderline for 2.73, 3.08 gears. Would work much better with 3.23, 3.42 gears and a 2000-2500 stall converter. More stall and more gear is a way to increase performance with a low comp, low hp motor.

Sometimes links don't work after a while for various reasons. So I'll give you some part numbers for the six cams in the links below. The Comp Cams part numbers are 12-230-2, 51-221-4, & 51-222-4. The Lunati part numbers are 60900, 60901, & 60902.

http://www.summitrac...erview/make/gmc

http://www.ebay.com/...0c87d63&vxp=mtr

http://www.summitrac...221-4/overview/

http://www.ebay.com/...=item2ecf4b38b8

http://www.atlantics...?idproduct=6635

http://www.alpermoto...ail&my_rate=JPY

Converters:

http://www.ebay.com/...h=item2c80c1615

http://www.ebay.com/...68af2f1&vxp=mtr

http://www.ebay.com/...2ea86d3&vxp=mtr

http://www.ebay.com/...c228e8d&vxp=mtr

 

[ponyakr]

OK ya'll, here's the deal. I'm still trying to come up with a reasonably priced forged rod / piston combo for the 350P. I'm sure ya'll have heard the old saying "You can't get there from here." Well that's the way it seems today. I've been calling around, to locate and price pistons, rods and machining possibilities. Here's what I have found out:

(1) Probe will not make a custom 350P piston.

(2) Icon does not make custom pistons of any kind.

(3) Wiseco will be glad to make custom pistons for you. Only problem is, their price is much higher than ROSS !

(4) The only guy at BRC who can give any info on their custom pistons is gone and may not even be back in today.

(5) Ohio Crank can replace the .990 bushings in their street / strip BBC 6.535 rods with .984 bushings for $150. So, that would make the price of the finished rods $219 + $150 + freight. That's almost $400.

And on top of that, they are out of the rods right now, and are not expecting any for at least two months, on the slow boat from China.

And even if they had the rods, those and the 318 MOPAR pistons are only a couple of hundred cheaper than Tomahawk rods and Ross pistons.

But hey, I ain't give up yet !

I've always heard "If there's a will, there's a way." You may be able to buy a set of the 5140 BBC rods off Ebay for $152 then have your local machine shop swap the .990 bushings for .984 bushings. If they will do it for $150, then you'll only have $152 + $150 = $302 total in the rods. So, if you add this to the price of the Wiseco 318 pistons, you come up with a total of $302 + $472 = $774 for a 350P forged rod / piston combo. That ain't cheap, but it's cheaper than the price of a set of custom Ross pistons.

http://www.ebay.com/...f05c120&vxp=mtr

http://www.summitrac...view/make/dodge

I need some help here guys ! I don't live in a city with a machine shop. So, for some of ya'll that do, I need you to inquire at your shop as to what they would charge to swap out the .990 bushings for .984 bushings--parts and labor. And I suppose you need to find out if .984 bushings are available with an OD large enuff to replace the .990 bushings.

Also, find out what the shop would charge to enlarge the .984 pin bore of the 318 pistons, and fit them with .990 BBC pins--parts and labor.(the cheapest pins available) When any of ya'll come up with this info please post it on this thread. Thanks !

 

[ponyakr]

OK, here's the latest 350P news.

(1) Got in touch with BRC. Same price as Ross--about $800.

(2) Talked to a guy at a big machine shop, who builds lots of Pontiac motors. He said they would hone the .984 pin bores in the 318 pistons to fit the .990 BBC pins for $10 per piston. And he said the .990 pins cost about $5 each. So, that makes the total cost of the finished pistons $472 + $80 + $40 = $592 + freight. That ain't cheap, but it beats $800 for custom pistons.

So, let's see how much it will cost to go with this forged combo, as compared to the cast piston combo. OK, I'll figure the total cost of the pistons at $615 + the cheap 5140 BBC rods $152 = $767. The cast piston combo is $188 for the pistons + $243 for the 5140 Pontiac rods = $431. So $767 - $431 = $336, So it will cost $336 plus any extra it costs to machine the crank, to go with forged pistons instead of cast.

So, depending on whether your local machine shop can swap the pins for the same price as this big shop I mentioned, I'll round It off and say it will cost about $350 to go with the forged pistons. And, of course, with either combo, you can upgrade to better rods for extra cost.

(3) Now, If you wanna build a 350P stroker, Butler sells a balanced cast crank assembly for about $2000 shipped.

http://www.jbp-pontiac.com/products/engines_assemblies/rotating_assemblies.html#407_413

I called them. They will sell the pistons separately. So, if you wanna buy the stroker parts your self and have your machine shop balance and fit the pins, you can probably save a few bucks. I'll check out some possible cheaper stroker combos in the next post.

 

[cajun]

Man Don you sure have a lot of info thanks. this will be a post for me to go over when I rebuild my 4 bolt 350.

 

[ponyakr]

Man Don you sure have a lot of info thanks. this will be a post for me to go over when I rebuild my 4 bolt 350.

No. actually you can rebuild your 350 4-bolt sbc a lot cheaper than you can build a 350P. sbc parts are just a lot cheaper than 350P parts. But one of these 4.25 stroke 350P motors will make a lot more low end torque than your 350 sbc.

It'll just take a lot more crawfish to build it .

 

[ponyakr]

OK, now for the 4.25 stroke 350P block stroker. This motor will have about the same cubes as a 400, but with a longer stroke and lighter rotating assembly, should have more low end torque and quick rev capabilities. I think it would make a great street / strip motor.

Butler sells the balanced 350P block 4.25 stroker assembly for $1898 + freight and shipping charges. So I'll call it $2000 total. You can have your choice of flat top or dish pistons, and three different rod lengths. And if you really wanna crank it up, you can upgrade to a forged crank. That ups the price to $2298.

http://www.jbp-ponti...es.html#407_413

Now it looks as tho you can save a few bucks on your stroker assembly by purchasing the parts separately, and having your (competent) machine shop do the fit and balance. The pistons are $675 + freight, without pins, everywhere I have found them. Have not found a custom piston any cheaper. I got some prices from a machine shop / Pontiac engine builder, He said BBC pins are about $5 each. And I figure he'll fit the pins for another $5 each. I'll estimate the total cost of the pistons to be $700. When you add the pins / fit, it brings the total cost of pistons / pins to be aprox $780.

The 4.25 stroke Eagle crank can be bought from Summit for $280.

http://www.summitrac...ew/make/pontiac

Most guys seem to like Eagle rods, so I'll add some 5140 Eagle rods to the mix. They're about $336 shipped from CNC.

http://www.cnc-motor...desc&q=sir6800b

Rings are about $126.

http://www.summitrac...05-65/overview/

Rod bearings are about $30.

http://www.ebay.com/...=p2054897.l5660

Mains are King # MB5523AM shown for $67 on Amazon when Googled.

http://www.amazon.com/King-Engine-Bearing-MB5523AM-Bearings/dp/B00B82HVNS

Most shops charge $200 to balance the assembly. So, let's add it all up and see if we can save anything when buying the pieces separately.

700--pistons
80---pins
280--crank
336--rods
126--rings
30---rod brgs
67--mains
200--balance
---------------------------
$ 1819 Total

Now the total could be slightly less than this, depending on your machine shop prices. Some shops will balance for $150. Some shops include the pin fit in the pistons and the rods as part of the balanced assembly work. Anyhow, it looks like you can save around $200 by doing it this way. But some had probably rather just pay the Butlers that extra $200, for their balanced assembly, especially if the shop they are using is not a Pontiac shop.

 

[ponyakr]

Now, I have come up with another possibly cheaper way to build a 350P 4.25" stroker. But it will require Pontiac spec rods--6.625. Now, in order for this to work, you'll have to mate the big end of the rod to the 2.20 BBC journal of the 4.25 stroker crank. The only way to do that is to use .050 undersize bearings.

Well, it just so happens that Summit shows a King brand brg for a Pontiac, in both a .050 and a .060 undersize. However, I couldn't find anybody else who showed these.

So, my question to you guys is, do any of you know if these brgs do actually exist today ? I called Summit to check on 'em. Of coarse, they don't stock these sizes. But he said the numbers were still in their computer system. I asked him to call King and see if they still made these brgs. But he said that King was on the east coast and had already closed for the weekend. So, I reckin it'll be Monday before I can find out about these brgs. Any of ya'll ever seen, used or even heard of these before ?

You could use a 6,635 BBC rod for this combo, but the extra cost of the rods, pins and machine work required, would make it no cheaper than a Ross piston stroker.

http://www.summitracing.com/parts/kgb-cr815cp050/overview/make/pontiac

http://www.summitracing.com/parts/kgb-cr815cp060/overview/make/pontiac

 

[ponyakr]

For those who have more $ to spend, you can buy some D-port alum heads for your 350P stroker. Butler offers Edlebrock D-ports with all sorts of options, starting from 65cc, and including larger CNC 'd chambers and other porting options. These heads have the heat risers like the stock iron heads, which when used with an intake which has the heat crossover under the carb, is supposed to be 50 state legal. They also have heli coil inserts for the rocker studs and exhaust bolts. Figure on spending between $2500 and $3000 to get a ready-to-run set with bolts. Stock out-of-the-box heads are slightly lower. Butler says the 350P block must be chamfered to clear the 2.11 intake valves. KRE built a set of their D-ports for a road course racer, using 2.08 intakes I believe. So Butler will probably build with smaller valves also, if you choose.

http://www.jbp-pontiac.com/products/cylinder_heads/edelbrock_aluminumD_Port.htm

http://www.krepower.com/Pontiac%20Aluminum%20D-port%20Cylinder%20Heads.htm

 

[ponyakr]

OK, here's another way to build a 4.25 stroke 350P block motor. The only purpose of this post is to determine if this combo will be cheaper to build than using the Ross pistons and 6.8" Eagle BBC rods. I haven't added it up yet, so I'll find out the bottom line cost as I develop this post.

Now, the reason I believe this might be a cheaper way to do it is because it uses stock length, 6.625" Pontiac rods, which are about $70-$90 cheaper than the Eagle 5140 rods. And because the pistons are about $300 cheaper than Ross pistons. Lets talk about the rods 1st. The cheapest forged 6.625 rod I am aware of is the 5140 rod from CP. They are $243 shipped. The best price I found for the 5140 Eagle 6.8 rods was about $336 shipped. So, that's a savings of $93. The Tomahawk rods are about $268 shipped. So that's a savings of about $68.

http://www.competitionproducts.com/5140-I-Beam-Rods-Pontiac-6625-Press-Pin/productinfo/4556/#.U15pfFVdVZ4

http://www.cnc-motorsports.com/catalogsearch/result/?order=relevance&dir=desc&q=sir6800b

http://forums.performanceyears.com/forums/showpost.php?p=5050633&postcount=1

Now, for the pistons, they are stroker pistons for a 318 Mopar. They're 3.94 bore which is a .065 over 350P bore. The price is about $491 shipped. So that is a savings of about $300 over the Ross pistons.

http://www.campbellenterprises.com/pistons/318-pistons-mopar-dodge-318-stroker-pistons.php#kbicon318forgedpistons

http://www.cnc-motorsports.com/pistons-1/icon-pistons/icon-ic846-030-forged-flat-top-pistons-3-940-bore.html

So, with the 5140 rods and the 318 pistons we can save nearly $400 off the price of our Ross piston stroker assembly. That's the good news. The bad news is that some of the other parts involved will reduce the savings a bit. For example: in order for the Pontiac rods to work on the 2.20 BBC rod journal of the 4.25 stroker crank, it will require .050 undersize Pontiac rod bearings. I just had a guy at Summit to call King Bearing to see if these were still available. He was assured that they are expecting a shipment which includes some of the .050 & .060 undersizes, which should be arriving by mid May. But the bad news is that these cost about $46 more than BBC rod bearings.

http://www.summitracing.com/parts/kgb-cr815cp050/overview/make/pontiac

Also, the 318 pistons have .984 pins. The Pontiac rods have .980 holes. So a Machine shop must hone to the correct size and press the pins into the pistons. I'l estimate the cost of that work at $100. So, if we add that to the extra cost of the rod bearings, we can subtract about $150 from our savings. $400-$150 = $250. So, unless there are some unforseen costs, we should be able to save between $200 & $250, by using Pontiac rods and 318 pistons. I'll explain all the parts involved in this combo in a future post.

Also, one other option is to use the Pontiac rods with Ross pistons. That would eliminate the extra cost of honing the rods for .984 pins. But, more on this later.

 

[ponyakr]

Breaker ! Breaker ! Breaker ! I just ran across a site which says they are the largest custom piston supplier in the USA ! So, I gave 'em a call. I talked to a guy from New Hamshire. He was not friendly at all ! But, he said he had been making custom pistons for 59 years, and had made more than anybody. He said he could make a set of flat top 350P pistons with any size and pin location, including the pins and locks, for $600 + freight, with about a 3 week wait time.

So, if all this info is true and this is a good quality product, that makes much of the info I've posted on this thread useless. It means that stock stroke and stroker 350P pistons with any pins and pin location are all no more than $600 + freight. That's a $200 savings, and makes the use of several rod lengths possible.

But I have never heard of these custom pistons until today. I don't know if they are any good or just junk. So, I need some input. Have any of you guys ever bought any of these pistons, or do you know anyone who has. Please check out this site and post your opinion. It's called Flatlander Racing. Do you think this is a good product or not ? Thanks in advance for your input !

http://www.flatlanderracing.com/pistons.html

 

[buddyfirebird]

ok ponyakr, im not trying to jump ahead of you but can I just throw a thumpr cam kit intake and carb on my stock 350 (currently 2 bbl carb) and have it do any thing? im just getting the car back from a body guy and really don't want to do a major job before summer. thanks for the info, ive been checking daily to read updates.

 

[ponyakr]

ok ponyakr, im not trying to jump ahead of you but can I just throw a thumpr cam kit intake and carb on my stock 350 (currently 2 bbl carb) and have it do any thing? im just getting the car back from a body guy and really don't want to do a major job before summer. thanks for the info, ive been checking daily to read updates.

Well, that's a good question. If the motor is original, then a performance upgrade might just cause a lot of blowby and smoke. If, however, it has had a good rebuild recently, then it should work OK. Go easy on the size of the "Thumpr" cam. A 350 is real sensitive to cam size. It's easy to over cam. It may sound good but have no bottom end at all, no vacuum, and real poor idle quality.

If it runs good now, I'd wait and plan the build. If you just can't stand it, I'd go for the intake / Q-jet swap instead of the cam swap. You can use those parts on whatever you decide to build. The stock Q-jet manifolds are good. But an Edlebrock Performer #2156 is lighter and will keep the carb a bit cooler.

techg8 on this site is a Q-jet man. He can fix you up with a GOOD rebuilt Q-jet or can rebuild yours. Those not familiar with Q-jets can really mess one up.