Carburetor Question.

[DoubleL]

I am doing some work on my truck this winter and I am planning on leaving the stock 283 alone for now. It is still in good shape. I had a 4 barrell manifold with HEI and a quadrajet on it which I intended to rebuild. The Quadrajet is shot, I think the PO used an impact gun to put it together and didn't real care what size screws and bolts he used I am looking for an affordable used carb. I can rebuild it with no problem. Do you have recommendations for a specific carb? Also, would it be crazy to rebuild my old 2-barrel and just put that manifold back on? Do you see an issue with the old manifold with the new HEI? Thank you so much for your input.

[AcampoDave]

Not at all crazy to rebuild the stock carb and re-use the stock manifold. The motor was designed to use them. The stock intake has smaller runners than the 4 bbl version which aids with throttle response at low rpm to give the motor that peppy feeling driving around town. It also accommodates a factory air cleaner (which looks great if stock is your style) and you could potentially save a few bucks using what you have.

However, If a 4bbl is your thing, then you would need no more than a 500 cfm. Edelbrock makes one and it's easy to rebuild, but it may also require re-jetting as most 500 cfm Eddys tend to be too rich for the average 283. Are the bushings for the throttle blades still in good shape on the 2 jet? By that I mean little to no side to side slop.

The HEI will be fine either way you go.

[Steeveedee]

Was there an adapter under the Q-Jet? That appears to be a manifold for a 4GC Rochester, or potentially for an AFB. There should be no problem with the HEI on that manifold.

[DoubleL]

Originally Posted by AcampoDave

Not at all crazy to rebuild the stock carb and re-use the stock manifold. The motor was designed to use them. The stock intake has smaller runners than the 4 bbl version which aids with throttle response at low rpm to give the motor that peppy feeling driving around town. It also accommodates a factory air cleaner (which looks great if stock is your style) and you could potentially save a few bucks using what you have.

However, If a 4bbl is your thing, then you would need no more than a 500 cfm. Edelbrock makes one and it's easy to rebuild, but it may also require re-jetting as most 500 cfm Eddys tend to be too rich for the average 283. Are the bushings for the throttle blades still in good shape on the 2 jet? By that I mean little to no side to side slop.

The HEI will be fine either way you go.

The more I think about it, I think I will put the original carb back. I'll check the bushing and rebuild it as neccessary. I do have the original air cleaner and I like the looks of it!
Thank you!

[DoubleL]

Originally Posted by Steeveedee

Was there an adapter under the Q-Jet? That appears to be a manifold for a 4GC Rochester, or potentially for an AFB. There should be no problem with the HEI on that manifold.

Yes, there was an adapter plate, Thanks for your help!

[AcampoDave]

I'm glad you decided to give it a chance. I have a stock 283 (except for an HEI and dual pipes) and you know, it really is a spirited little engine. I took the time to really nail down my timing curve using an inexpensive balancer tape so I could see the real numbers. I finally landed at 16 degrees inital advance with 14 degrees mechanical advance and it's all in at around 2000 rpm. My vacum advance pulls an additional 22 degrees plugged into a non-ported source on the carb. I have managed to score a couple of additonal 2 jets over the years and they have been useful for parts. Don't forget that the oem manifold has 2 holes going to the baseplate of the carb to allow exhaust to warm it. The carb has a cast iron base and uses a metallic base gasket to withstand the heat.

Edit.: the other cool thing about the oem manifold is that it has the threaded boss in it for the alternator tension slide bracket, which I'm not seeing on that 4bbl manifold. (Huh, my pic went sideways on me but oh well.)