thanks for the replies. as for now i don't have a cat (i don't think it came stock with one), but still have a muffler. i want to get a single 5" stack straight piped, i was just wondering that as long as it ends behind the passenger cab i would be alright. also a big rig driver the stack end has to be at least 6" above the top of the cab, don't know if thats true for passenger rigs or not.
travis