PLEASE HELP
 

ok so here is my dilemma I have an 87 mustang hatchback gt with a built motor that is part of the problem. I was told it ia a 347 stroker. that's wat I was told. I know it has afr aluminum heads bbk 70mm throttle body and spacer eldebrock intake and bbk long tube headers and roller rockers 1.7 and c&l cold air tube. my issue is I am getting back fire and loss of power on acceleration. I have changed the plugs wires cap rotor and egr valve and coolant temp sensor. still have this issue was told I need mass air sensor but he did know which one to put on since he did not know cam size and exact injector size. so I'm looking for some suggestions we do know it is not the oem maf. my injectors are blue on top and black on bottom.... so which maf do I need and or what do u suggest is next. guy that worked on my car says from wat he can see build was done right but they may have lacked on the small details. o and the factory computer has been removed and aftermarket is in place where battery was and batt has been relocated to trunk.