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-   -   7028267 Quadrajet specifications (https://forums.maxperformanceinc.com/forums/showthread.php?t=833366)

John Milner 08-22-2019 06:46 PM

7028267 Quadrajet specifications
 
Does anyone have anything that will show what jet sizes, metering rods, and secondary hangar/rods a 7028267 Quadrajet is supposed to have?

Tinkerer 08-24-2019 12:33 AM

The part numbers follow, according to Delco 9C-6030, Nov. 1971 (Maybe someone else can match the part numbers to the sizes?):

1968 400/428 HO, Man. Trans.

Jet - 7031972
Rod - 7031841
Secondary rod - 7034377
Hanger - 7034522

Bill

Tinkerer 08-24-2019 12:59 AM

Some Googling found this:

http://corvette-restoration.com/wp-c...arb_Tuning.pdf

It lists your carb.

Bill

John Milner 08-24-2019 01:13 AM

Thank you for the link and for the part numbers. That is exactly what I was wanting to know. I appreciate it.

Cliff R 08-24-2019 01:11 PM

It will enjoy a slight recalibration for this new fuel. Those carburetors were set-up for stock applications and the fuel had more BTU's back then.

We add a little clear across the load speed range, otherwise you are likely to get a customer complaint as it will be just a tad lean.

If you've made any engine changes at all it may need a bit more, depending on the static compression ratio and cam specs.......Cliff

John Milner 08-24-2019 01:38 PM

Thanks Cliff. I have not selected a cam or anything for the WS 400 yet. I do want it to be close to stock. Sounds like the carb could use some re-calibration to get the most out of it with the new fuel.

Cliff R 08-24-2019 03:11 PM

I noticed the change quite a while back and "adjusted" the tunes for it. If you leave them stone stock there can be some light surging at part throttle, "flat" on acceleration, and down on power some. Full throttle isn't too bad as they were a little "fat" there anyhow.

A cam change certainly requires some custom tuning, or the engine or no one else is happy!.......Cliff

Tinkerer 08-24-2019 04:58 PM

The hanger that I listed is what the manual has for a service replacement. It is a "V" hanger. I assume that your carb. would have had a different one from the factory.

Bill


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