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Hello looking for some technical assistance , I have a 1978 C3 PaceCar with a L48 which has an Edelbrock carburetor in place. I have a Qudrajet which I would like to mount however there are no tubes near the top of the quadrajet identifed as B and T on the carburetor . The hoses to these areas are T goes to a temp sensor/switch from the top of the manifold to the carburetor . B goes to the charcoal canister which is mounted to the inside left fender. Everything else seems to be the same. I am trying to understand what will occur if I mount the quadrajet carburetor or should I leave the edlebrock alone . Any assistance or information would be greatly appreciated
Last edited by Rookie One; Mar 22, 2021 at 06:37 PM.
That Edelbrock carb is essentially a 'real' Quadrajet. Edelbrock bought the tooling for that carb from Rochester when GM 'quit' doing carburetors on their engines.
If it seems to run fine, performance and fuel mileage are acceptable, leave it there.
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by Jebbysan
The "new" carb is pre-1978. Jebby
That's correct. In 1978, the Q-Jet on the Corvette was changed significantly from the 1976 - 1977 Q-Jets by adding the large EVAP nipple in the front of the float bowl. The carb you have pictured is a pre-'78 carb that will not directly swap onto your '78 engine without significant modifications.
1976 Corvette Q-Jet. No vacuum nipple at the "B" position, and no large forward bowl vent for the EVAP canister (carb pictured has not yet been outfitted with the vacuum hose to the choke pulloff):
1977 Q-Jet. The "B" vacuum nipple was added, but still no 3/8" forward bowl vent for EVAP:
1978 - 1980 Q-Jet with both the "B" vacuum nipple and the large 3/8" forward bowl vent tube for hookup to EVAP. Hot air choke was changed to electric choke in 1980:
Carburetor problem
