Originally Posted by 75gmck25
I was rebuilding a carb I bought from the junkyard (from an '86 Chevy truck) and decided to install the bushings just in case. However, based on the very limited play I found when I pulled out the shaft, it probably did not need the bushing kit.
The kit I bought from Cliff's performance came with 2 sets of bushings, so I'll probably eventually use it for my original '75 vintage Quadrajet.
I switched to the later model Quadrajet because it had the externally adjustable APT and some other improved features. It was also one of the last models they made before adding any electric controls, so it was an easy replacement for my old carb.
The mid-'80s non feedback
truck carbs are among the best Q-jets out there for building a performance carb: They are the 800 cfm casting, have top-mounted APT access, use an electric choke, are correct for OD transmission TV cables (be sure the throttle arm is correct if you want to use a detent/TV cable attached below the throttle centerline; manual carbs are sometimes missing this), and are often in way better shape than a carb from the '60s-'70s.
Even the dual capacity accelerator pump-equipped carbs are good cores, and most guys don't realize that the dual capacity pump carbs are non feedback so there's a better than average chance of funding one.
There are Q-jets that are BOTH dual capacity pump AND feedback, how to tell which is which can be seen here