Have a lead on a '76 Pontiac Trans Am 400 Have learned that the car came with an 800 cfm quadra jet carb. Regarding the primary's and secondary jets, What are they...?
Probably a 17056264. Quadrajets only have primary jets, with primary metering rods. The secondaries have the fixed orifice with secondary metering rods, no secondary jets. I am not sure what jets came in that carb originally.
The 1975 to 1979 Pontiac q-jets (except those on the 301's) are at the top of the list for the best q-jets ever made for high performance use. I use a 1977 Pontiac q-jet on my own engine, and it has outran every Holley, Demon or Holley clone that's ever been back to back tested against it, dyno and at the track. The dyno shop that I use actually hates that carb, and usually throws some fancy Holley clone up against it with anodized metering blocks and all sorts of other modifications to make more power, but to date this has never happened. The part number on mine is 17057274, and a grinder or sanding roll has never touched it. It's recalibrated exactly for my application, and has a few minor modifications to keep the fuel I the bowl for hard launches (drag racing), and an electric choke conversion. As good as the Pontiac units are, any later model large cfm casting is equally as good when correctly set-up for the application, so no need to hunt down Pontiac carb instead. The later Pontiac carbs also have a large front vent, which can be a down-side to using them in non-Pontiac applications......Cliff
