I installed a 350 rocket into my 72 cutlass a few days ago so I'm doing testing and tuning. One problem that I'm encountering is while I'm driving down the road and press the brakes the car acts like it wants to cut off. It only happens at low speeds.
Does anyone know why this is?
Any other information you guys need?

 

Carb adjustment/ idle too low, timing, if you changed distributors, maybe not having 12v at coil??

Probably need a bit more info on your setup?

 

Since it happens while braking, does it change pedal feel?
If so, could be the booster, especially if the car sat for a while.