Hello everyone. and please help

[vince23]

hello my name is Vince and i am new to mopar chat.
i need some help with my new 1973 duster. it has a slant six with .040 over pistons and i believe a 3/4 cam. i have replaced everything in the engine complete rebuild except for the power brake booster which is on order for tomorrow. my problem is i can not get it into time and when i put it into reverse and sometimes drive it will stall. could these problems be cause of the booster???: