Cliff's Quadrajet Parts and Rebuild Kits
Quadrajet Problem Solving => Quadrajet Parts and Numbers => Topic started by: DaDuck on February 10, 2021, 08:22:29 AM
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looking for information on factory guts that would have been delivered from GM in my 1977 Grand Prix (400 Pontiac engine code XA) Rochester Quadrajet. I pulled the carb apart to make a list for clean/rebuild and found 72 main jets and DB rods....I am thinking those were not original size jets for emissions compliance in 1977?
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DB secondary rods are correct. That carb either used 71 or 72 main jets from what I can remember. I use the same carburetor on my own engine, excellent units. It's a completely "stock" unit, no grinder or sanding roll has ever touched it. It is recalibrated for my application, and to date NOTHING we've ever tested against it on the dyno or at the track will outrun it. Believe me they (the dyno shop I use) has tried many times and none of their fancy Holley or Holley clones will make more power or quicker in ET or MPH!
When it comes to rebuilding and setting the carb up keep in mind that this new fuel doesn't have the same formulation as the fuel that carb/engine combo was calibrated with so re-using the stock jets/metering rods may not come up with the best end result. It's also rare to find one of those engines unmodified and ALL of the original emission related components in place and functioning correctly.
Not really a big deal as the carb has an APT system and outfitted with the right parts you can easily dial it in for any application.
I would recommend one of my rebuild kits and if you want more information and tuning parts, etc, call the shop and I can put a custom rebuild kit together for what you are doing.........Cliff
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Thanks Cliff,
I will call next week and discuss what you think I need.