major a$$ problems with my stang

First of all i did the 5 lug conversion with the rear drums and then i didnt get any brakes, no pedal at all, so i decided to change to rear discs and then put all the right parts including master cylinder, proportioning valve 3-2 port conversion, still no brakes, then the battery dies, so i put a new battery in there and all it does now is miss like crazy, im pulling my hair out, i dont have the time or resources to fix it so im either going to try and get 4500 for it or part it out, any suggestions.

well i figured why it was missing, 1 plug was fouled caused by a bad injector i replaced the injectors and plugs and it runs like a champ, but the brake system.

i did bench bleed the MC, and the brakes numerous times, i do have some kind of not hissing noise like air escaping from a line but like a rattle and hissing at the same time inside the car. also when you un plug the vacuum from the booster and plug the hole the brakes work manually