350 stalling

[Attrait]

I have an 89 RS the engine has been swapped for a 350. Problem is under braking and hard turns, engine all but stalls. its set up with serpentine system from a 4.3, but the belt is new and doesn't feel too tight. Please help this is really getting on my nerves.

[1992RS]

your car wouldn't happen to be an automatic would it? It sounds like the converter if it is.

[89IROC&RS]

whats your gas level at????? even at a quarter tank, hard braking and hard right turns can starve the pump and the engine will stall. but yeah could be a converter, could also be a leaking brake assist cylender if it leaks vacume with the brakes on, then you will get a stumble and rough idle, in severe instances, it could stall the engine.

[Attrait]

Gas level is not a factor, does it full or empty. It IS however, an automatic, hoping that's the problem, it's time for a manual anyway. Thanks a lot guys!