well folks , it all depends on if his engine is stock or he has bolt on mods. basically stock SR's are not prone to excessive backfiring which is what it sounds like he has . I think he might need to do some tuning to it. Also is the car running rich? What kind of fuel pump are you running? If your running a stock fuel pump please please please do yourself a favor and put in a hight pressure one.
Stock KA fuel pumps were designed for 270 injectors not 370(stock SR injectors) . We would have to have more details on the swap but yes the best thing to do is take it back to the shop that swapped it for you and have them tune it.
Oh yeah folks any shop thats worth its weight in SR swaps will know how to tune the engine good. If they do not you do not want them doing your swap. Lack of SR tuning knowledge translates to lack of doing SR installs on a regular basis.
