I have a 67 Firebird with a stock 400 engine. I have been told different things about carbs. Does anyone know which carb works best with this engine ? I have the original quadrajet I took off because it was driving me crazy and could never get it right. I put on a holley but I dont feel I am getting the full potential out of the engine. Any suggestions ? Thank you

Qjets IMO work best. Holleys suck and are gas guzzlers.

All above depends on how well the person can tune.

What about the Q-Jet is driving you mad?

I agree, Q-jet is the way to go. However, I'd have it rebuilt/set up buy someone who knows EXACTLY what they are doing. My friend Mike rebuilt mine a few months back and the car ran sooooo much better in every way!