Touble Starting

I have a friend that just put a cam in a 6.0 and he is having problems with it starting. Sometimes it starts fine, and other times it wants to backfire before it starts. He changed the cam sensor and it still does it, I was wondering if something could be wrong with the cam or the tune?

did he get a tune for it?. or maybe he needs to do a crank relearn or idle relearn

might be a ls2 cam..they dont have the relucting ring on the back of the cam that the cam sensor reads off of

He has a mail order tune, and the cam is a Ls1 cam. Its a Lunati cam