[firebirdfan88]

So I currently have a 455 with a Holley 650 spreadbore stuck on top. My main question is what came factory on these Pontiac motors. After a ton of research I have come up with that it is a q-jet 4 barrel. My carb has been tampered with by the previous owner. I was told holleys are a pain to keep tuned witch is why I'm looking for a replacement. Can I source a rebuildabke core from a junk yard if so what car/engine combo. I'm still new to carbs so any info is greatly appreciated. And yes I can handle flaming as long as there is good info along with it.

 

[tjs]

Just get a propley set up pontiac QJ,I think they were 750s.There are lots of junk cores out there so be carefull.Cliff Ruggels and SMI both to very good OJ rebuilds.Cliff is about 6 month behind im told on his rebuilds and dont know if he has done carbs on the shelf to offer customers.I know SMI does.Tom

 

[ponyakr]

".. I can handle flaming.."

I'm sorry, but I'm an old country boy. I don't have a clue what "flaming" is. Oh well.

Anyhow, all 455 engines came with Q-jet carbs. Most were 750cfm. A few were 800cfm.

The 650 is too small for a 455. IMO.

"...Can I source a rebuildabke core from a junk yard..."

Maybe. Depends on the yard. The best Q-jets came on '76-'79 cars. Some of the '68-'74 carbs are good too. Also, Edelbrock made some good Q-jets. These are actually newer than the GM Q's.

Besides cfm rating, there are other differences in Q-jets. Most BOP Q's have a straight front fuel inlet. Most Chevy and all Edel Q's have a 90 degree, sometimes called a side inlet. You can use either kind, on a Pontiac engine. But, there will be some additional plumbing, for a side inlet Q.

Most every car maker used a different throttle lever/cable hook up. So, depending on the exact model Q you get, you may have to fab your own throttle linkage. Also, some Olds and Buick Q's had a throttle return spring that pulled from the front, instead of the rear.

All Pontiac Q's beginning in late 1970 thru '79 had a big "smokestack" bowl vent, which requires a hole for it, in the air cleaner base. Also need to use a rubber grommet to help seal the hole around the vent, to prevent any trash or dust from being sucked into the carb.

The '76-'79 Q's have a desirable adjustment feature, which is referred to as an APT.

If you don't want to have to deal with the big vent, but would like to have the APT feature, you can source a Q for an Olds 403 engine. There are others, but these came on lots of 403 TA's, in the late '70's.

If you'd rather just buy a good Q, there are some good builders around. These 1st two I'll link are both known as good Q-jet sources.

http://www.everyday-performance.com/quadrajet_carburetors.htm

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

There are lots of Q's for sale on Ebay. Some are good, but some are probably not so good.

http://www.ebay.com/itm/Edelbrock-Quadrajet-1903-Remanufactured-Carburetor-795-CFM-/171961410486?hash=item2809b2e3b6:g:75QAAOSwYHxWMVZo&vxp=mtr

Summit sells UREMCO rebuilds which may be OK. I think a member here bought one of these not too long ago. But, right now, I can't remember who it was. Maybe he'll see this post and tell us how his UREMCO is doing. :smile22:

http://www.uremcoinc.com/carburetors/view/35919

http://www.summitracing.com/parts/urm-11-1230

http://www.uremcoinc.com/carburetors/view/37711

http://www.summitracing.com/parts/urm-14-4200

 

[JoePeek]

I agree, a 650 is too small for a 455. Everything I have done to make 455's breath better always improved the performance (intake manifold and carb). Changes I used to think were maybe going to kill the low end on a 455 never did. When I went with an Edelbrock Victor manifold I figured I would be giving up some low end, but that did not happen. Perhaps conservative thinking was from the times I had Chevy, or Pontiac 350's that I had to be careful not to over carb, or the low end would go soft. Not so with a 455, they seem to respond great in the 3500 to 5200 RPM range when you put a big carb and single plane intake on them.

 

[KeyKeeper]

Don whats a solid buildable 800cfm qjet worth?

 

[ponyakr]

"...whats a solid buildable 800cfm qjet worth?"

That depends on EXACTLY which 800cfm Q-jet it is, and EXACTLY how good of shape it's in. :yes

If it's a good clean original, with all it's original parts, I'd say it would have to be worth at least $50.

For example: UREMCO charges $67.50 core charge for the Olds Q, and $45 for the Pontiac Q, which I posted links to.

http://www.summitracing.com/parts/urm-11-1230

http://www.summitracing.com/parts/urm-14-4200

Their core charge for this '73 800cfm 455 Buick Q, is also $45.

http://www.summitracing.com/parts/urm-1-268/overview/make/buick

I don't know what the rebuilders will pay for a good core, if you don't buy a carb. I suspect it will depend on exactly what it originally came on. The correct numbered Q for the old and especially the very rare Musclecars, can be worth thousands.:shock:

Whereas the Q's that came on big heavy family type cars, although they may be just as good for performance rebuilds, will not bring as high a price. Q's for the numbers matching Performance car resto builds are the ones that bring the high prices.

So, bottom line, the short answer to your question is that it depends on the ID number and condition. :smile22:

 

[KeyKeeper]

Well the one I got is for a chevy. it has the 90 degree inlet

the numbers on it seem to point to very early 70s. maybe some chevelle or impala guy might want it. Shafts seem tight in the base plate but could bush them I guess if someone wanted them crazy tight for idle quality adjustment.

I tore it down, and holy hell you could eat outta its so clean. The only thing on it is the typical black soot in the barrels. Other than that its spotless. I thought about running it on my bird instead of that crappy Ebrock I have and wouldnt have to spend the money on a demon or holley but not sure yet. I do know someone has bent the secondary metering rod support and they are all uneven lol.