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Discussion Starter · #1 ·
My old 400 let loose. Picked up a 1970 400 with #13 heads. Had been rebuilt but dont have any cam specs. Pulled it apart to regasket, new melling oil pump, timing chain etc. Bearings and cylinders all looked great. CC'd the chambers and heads, pistons had small amount machined out of center. Calculated right at 9.4-1 for compression. My old 400 had a holley 600 on it. Never cared for it. Picked up a used Edelbrock 750 for 10 bucks and rebuilt it. Dont like the way it acts. Can't get the off idle stumble to go away and it idles down to about 1500 rpms then slowly idles down to 700 rpms. Have run alot of edelbrocks over the years on chevys and loved them. My question is where can i get a quadrajet that i can run out of the box for a fair price? Car is a 67 with a munci 4speed. wide ratio and tall gears. Not a race car just a nice cruiser. Motor does have a nice lope to it. Full length headers and an old edelbrock performer. HEI ignition etc. Have 2 holleys and an edelbrock. If i'm buying a new carb i want to make sure i get it right the first time. Thank you for any and all help. Also will the quadrajet bolt up to the Edelbrock intake? Have a Lokar throttle cable so that should work and a manual choke cable.
 

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I recommend a Q-jet. But, if you have a Torker 2 intake, a Q will not bolt up to it. You'll need a Performer, Performer RPM, or one of the Chinese RPM knockoffs.

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

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

If you have a Torker 2, and want to keep it, then the cheapest good Holley may be a rebuilt 3310-1, which is called a "780". It has downleg boosters and vac secondaries. There are usually several cores and rebuilds for sale on Ebay.

If you have the funds for a new Holley type carb, a quick fuel SS-680-VS might be a good choice. They come in several cfm sizes.

http://www.gtoforum.com/f12/opinion-carberater-400-motor-86857/index2.html#post624025

http://www.quickfueltechnology.com/carburetors/street/ss-series/vacuum-secondary-1.html

http://www.amazon.com/Quick-Fuel-Technology-SS-680-VS-Carburetor/dp/B003M8YV4I
 

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JMO,if you want to run a square bore carb and want a good driving unit I would search out a good mid 60s pontiac AFB.Not a E afb.They are easy to work on,will be very close on the setup.E AFBs will work but take a lot of work to get everything right for street driving.If me though I would just get a factory intake with a properly built QJ.Tom
 

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Discussion Starter · #4 ·
Have the old style pb4 edelbrock performer intake. Will the q-jet bolt right up without adapter? Anybody recommend a good supplier for q-jet?
 

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If your in a hurry contact Sean at SMI in huntington beach ca.I was there a month or so ago and he had pontiac OJ carbs on the shelf.He owns and drives a pontiac so they can be test run on his car.When I was doing a RA III engine he put my carb on his car to be sure there were no issues.Tom
 

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Discussion Starter · #6 ·
Thanks Tom. Just want to get running right. I will contact SMI. So far past my original plans on bubget. Just the way it works. LOL. Planned on Vintage a/c and a 5 speed but when motor let loose that went way down on the list. FYI for anyone else building a motor. My original was a 75 block. The solid pins that locate the main caps should be replaced with the hollow roll pins. These blocks will split at the pin and let the cap turn just enough to send metal from the bearing through out the motor. Mine was rebuilt before i bought the car but i based my offer on not having to rebuild. Lesson learned. On the bright side i ended up with a 70 motor out of a formula firebird, much better casting.
 

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Actually the solid pins are far superior than hollow roll pins!My machine shop replaced the hollow pins on my 301 turbo block.Tom
 

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Discussion Starter · #8 ·
Yes depends on the casting. My old old block was a 400 #57755. Did alot of research on that casting. Its the weakest of the 400's. Not saying it's bad but wasn't strong enough in the web area around the pins for the setup they had. They recommend hollow pins on those castings for anything other than a moderate build.?????
 

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For the off idle stumble, are you running manifold or ported vacuum to the distributor? Also, what setting are you using for the accelerator pump on the Ebrock? They are kinda finicky till you get the pump rod sorted out in the arm. I had issues with mine doing the stutter take off as well, and had to move the push link on the accel arm one hole down and it cured it.
 

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Discussion Starter · #12 ·
Ported vaccum and have tried all 3 positions on accelerator pump. Will keep messing with it. Starts up nice and runs good just stumbles off idle.
 

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One other thing, the ball and square shaped weight in the "squirter" assembly may be sticking. Mine wouldn't squirt gas till it got warmed up. I tore it apart and cleaned it out with some B12 and it worked normal afterwards.
 
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