77 Quadrajet

[Steve Junkersfeld]

Hello, A little carb cleaner around the base of my 77s Qjet confirms that I have a vacuum leak at the base of the carb. I am going to have the carb rebuilt and want to know if the throttle plate can be trued up (I guess the same as you would a head). If not, is there a source for a new throttle plate? Thanks Steve

[Clem Z.]

Re: 77 Quadrajet

a good machine shop can fly cut the throttle base plate flat. they can check using a straightedge to see if it is warped. the leak could also be worn throttle shaft bores so i would check that also.

[Joe C.]

Re: 77 Quadrajet

Steve:

As Clem says, it is easy to true up your carb base, but if there is a problem with that, then there is a good chance that there are more problems elsewhere. Send it out to a Rochester Quadraj..k expert for a complete rebuild. I know some good Holley guys, but I cannot help you with the Quadraj..k.

Joe

[Steve Junkersfeld]

Re: 77 Quadrajet

Clem, Thanks for the advice. I'm sure that the shafts can be bushed - I'm having the carb work done by a Corvette guy up in Maryland who will flow check the carb after he's completed. Steve

[Steve Junkersfeld]

Re: 77 Quadrajet

Joe, Thanks for the response. The guy who is rebuilding it has a flow bench so we should be able to get all the leaks worked out. What is the old saying "there's no Corvette problem that enough money won't fix". Steve

[Joe L.]

Re: 77 Quadrajet

Steve----

As others have mentioned, it should be very possible to get your carb throttle body trued by a machine shop if it's necessary.

In the very unlikely event that you need a new throttle body assembly, the only source for these was GM/Delco. Unfortunately, the throttle body assemblies for all 1977 Rochester Q-Jets are long-since discontinued, as are the throttle body assemblies for ALL Corvette Rochester Q-Jets.

[Steve Junkersfeld]

Re: 77 Quadrajet

Thanks Joe - if I do need one, I'll get a junkyard or ebay carb and see if I can get a useable plate. Steve

[Joe L.]

Re: 77 Quadrajet

Steve-----

The problem is that there are many different configurations of these throttle body assemblies, especially for "later" Q-Jets. In fact, there are 3 different part numbers and configurations specific to 1977 Corvettes and these parts aren't shared by any other year Corvette. They may be used on other Q-Jets for other Chevrolet models, though.