Pontiac modified the fuel bowl by removing one of the booster rings for 1971 to increase CFM and used it on all the 455HO and the 400's with a manual transmission. As I've come to understand it, this single booster ring presented some low idle/light throttle driveablility issues to the point that many original owners apparently had dual booster ring fuel bowls/carburetors swapped in place of the original unit. Pontiac went back to the dual booster ring 750cfm fuel bowl for 1972.
Buick revised the casting, and as a result have an 800cfm dual booster ring fuel bowl starting in 1971; I don't have a full application listing, but understand they were only put on the higher power 455 engines.
Pontiac first used the "Buick designed" 800cfm fuel bowl in 1973 with the SD455, then adapted it to everything from 1975 forward.
I am unaware of Chevrolet engines EVER using an 800cfm Quadrajet - but suspect that some applications used them after 1975 or 1976.
As far as I'm aware, all 1967-1969 Chevrolet Quadrajets were visually identical... I have only owned a few.
-- Edited by unruhjonny on Monday 27th of August 2018 03:40:10 PM
__________________
1970 Formula 400 Carousel Red on black (std) interior "no drivetrain option" car (same base drivetrain as GTO) 1:411 1970 Firebird Formulas originally sold in Canada
