ever since i bought my car its had poor braking with a hard pedal. all new calipers all around, adjusted the rears multiple times, prop valve spring mod and new master. its getting better, but i dont have a lot of vacuum. i thought of doing hydroboost, but want to try a new booster. pedal is firm, holds vac for a few days. about half way though the pedal gets hard. is there a bigger booster i can run? if im not mistaken, the stock is a dual diaphragm?

How much vaccum are you making? If its not enough, a larger booster wont help.
Cam specs?

cant remember exactly, 234 duration, 490 lift. no clue on how much vac, but when revved the pedal will go down easier. it was like that stock and the only thing left is the booster