1979 L48 Quadrajet rebuild

Another thing to do is use a straight edge on all the flat mating surfaces to make sure there is no major warpage. 

Cliff also has a good book on rebuilding q-jets.  I used it along with Doug Roe's book on Rochesters.  

Sarge81 said: Being a common issue with Rochester carbs, especially 4 spd. cars you might want to also check your primary throttle shaft for slop in it. If you grab the throttle linkage where the throttle cable goes to, try to move it forward, backward, up n down. If there is excessive play you'll want to do or have a bushing kit installed. Otherwise you'll have a vacuum leak there and you'll never get a solid carb adjustment after a rebuild. 

daveo76 said:
Hey, Sarge - what is it about the 4 spd cars that exacerbates this problem?  I've never heard that bit of trivia but I've lived it since my car is a 4 spd and the shaft was pretty sloppy.  

Automatics your foot is more steady on the gas since the transmission is doing the shifting for you, hence less wear on the primary throttle shaft. 

On Rochester carbs the throttle shaft is steel and the base plate the shaft sits in is aluminum. That's where these bushing kits come in handy. The shaft will then sit in a brass/bronze bushing instead of the softer aluminum.

Adams' Apple said: Sarge is right, plus, manual trans cars usually have a little stouter return springs on the carbs, which adds to the accelerated(pun intended) wear on the shaft bores.
The main thing to remember about shaft bore wear is....Rochester/GM never intended for these carbs to still be running 25-30 years later. Back then, 10 years was a good run, if they lasted that long. So why bother using bushings there to start with? Even now, with throttle bodies on infected cars, there are shafts running in bare, untreated aluminuminum, or even magnesium in some cases.