i have recently traded for a 81 chevy truck and he told me that it was shoting gas out the carb. when i got it home it wasnt shoting gas out the carb it was back firing through the carb but it was running.So i got it up on (tdc) top dead center and it was 180 out. I got it set right now and rewired the distributer and now i cant get it to fire.I need so help on what to do next.