elis94camaro

Ok so my 1994 camaro z28 has been driving me crazy with this popping noise it makes when Im backing out of the driveway with the wheel turned to my left in the morning.It also does it during hard braking and the noise comes from the front passenger wheel or so it seems.Im really clueless as to what it could be and i have come to the conclusion that maybe its my longtube headers hitting the tranny, but i really dont know.The noise itself is a loud pop and always happens when in reverse turning the wheel to the left.So if anyone has any advice please do share and to those with pacesetter longtubes let me know if you car pops too.Any help is greatly appreciated,Thanks.