As an owner of an Automotive Repair Center I disagree with your answer to Hali the Librarian. Almost all quadrajets and 2bbls look the same but GM along with all of the other manufacturers used very specific spec’s for each vehicle as far as jetting , float levels, choke settings etc. Buying a carburetor off the internet a person would have no idea if the settings internally were right for their vehicle… We rebuild a lot of carburetors still along with repairing fuel injected vehicles.
Almost every time we are sent a vehicle so it can pass an emissions test we find a replacement carburetor that is not the correct one for the vehicle. Unfortunately the aftermarket tries to combine a lot of part #'s into one. This allows them to sell you a carburetor that looks the same but does not have the proper jetting - Sometimes thru research I can find the jet sizes and either drill them out or fill them and redrill them to the proper size. So the best choice is to ALWAYS have the original carburetor repaired. We also replace a lot of ignition modules that are built by an aftermarket company that tries to combine to many cars into one module. Usually installing the factory correct module corrects the timing equations so the vehicles will pass emissions.
Dennis - MasterTech Automotive SLC, Utah
What if the carburetor is not there in the first place or is the wrong one to begin with? I agree that the original should always be rebuilt but that’s not always possible. I bought many Holley carbs in the past and you can get one that is engineered for your particular engine without much difficulty. I would never by a carburetor offline from a private party. Who knows what you might get.
Dennis, “The Show” are all repeats, some many years old…The live broadcasts ended two years ago…I agree with your observations concerning “rebuilt” carburetors…Most of them are junk and must be rebuilt again by the installing mechanic, if he is willing and able to do that…Once the jetting information is lost, the job becomes hopeless unless you are willing to spend many hours doing the research and locating the correct parts…