Also suspect the intake gaskets, it wasn't running this bad before you swapped them was it?
A good set of carbs will run as good any four barrel if set up right. Dad's '65 Pontiac Safari wagon came with trip-power and ran for 25 years without any problems. It's all come downs to the setup and proper carbs. The big Pontiac's used vacuum operated end carburetors, either on or off, no part throttle. GTO's used progressive linkage.
If you are trying to use standard 2GC carbs on the ends, it's not going to work. The throttle shafts and butterfly valves are special to end carbs to help in sealing. You can replace standard ones with the correct ones from online venders. Google trip-power throttle shafts. True tri-power shafts and butterflies and much thicker so the can be forced shut for a true 100% seal.
If yours runs correct with the outers blocked off, ( solid gasket under each one ), thens it's just a matter of sealing. If it still acts up with the ends blocked, you have intake or center carb problems.
Don't try to work with all three carbs and intake at one time!
Joe
