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Old 11-08-2012, 08:28 PM
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Originally Posted by gmtony55 View Post
I do have another part to this question. Is the stock carb on my 83 elco something I can transfer over or not?

It is a 4 barrel Q-jet
Yes, the Q-jet will work fine. You might want to tune it to match the engine its going on, but that would be the case regardless of what carb you were going to use. But if you want to use the Performer RPM- which is a very good intake- the Q-jet won't bolt up w/o using an adapter unless it's the Q-jet model RPM. In most cases an adapter will not be something I'd recommend. But unless you wanted to use another intake or a different carb, that's the route you'd have to take. And there is at least one test that shows only a very small loss using an open adapter to mount a Q-jet on the squarebore RPM intake.

If you DO use an adapter, use something like Edelbrock p/n 2693. Summit sells a similar one for a lot less although it might not move the carb back 5/16" like the Edelbrock adapter does. What you want to avoid is the 4-hole jobs (like Proform p/n 66253).

The Q-jet carb will almost surely be the 750 cfm casting, not the 800 cfm casting, although in practice there's very little real-world difference in the performance between the two. The 800 cfm casting does have a slightly larger primary bore and venturi, but compared to most any other similar size carb the primaries are still smaller- which equates to good throttle response and potentially better mileage.

BTW, it's a little known fact that the V6 4.3L GM trucks in the later years (up until '86) used a non computer controlled Q-jet w/the 800 cfm casting. I have one right here from a '86 4.3L V6 Sierra! Good place to source a Q-jet.

Good luck.
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