Ive got a 94 trans am with a few issues. first off when im running at low rpm's in fifth and sixth gears theres a bumping underneath the car near the mid rear of the car. it sounds and feels like the drive shaft or possibly the trans mission is banging or binding off something. it feels like there is loose play in the drive shaft. my second issue is the stuttering i get when im in the gas. ive got a comp cam and valve springs ported and polished heads with a ported lt4 intake and also a polished crank. i smell a strong hint off gas when it putters. im not sure if its my fuel system and i might need to up the injectors. i really need help.