my friend is doing a 2.5 custom mandrel bent piping catback to a magnaflow universal muffler..the thing is he doesnt know which model to get..he would need a 2.5 inlet to get welded correct? but they dont make 2.5 inlets..they have 2.25 or 3..i was thinking 3 since they were going to weld it on anyways it wouldnt matter..would 2.5 piping to 3in muffler straight through be ok? as long as he isnt bottlenecking..also..what size tip would you recommend for a g3 intgra..its either 4 or 7inch long..?thanks

 

2.5" to 3" would be fine but dont go 2.5" to 2.25", that would be a bad idea, its always better to go small to big rather then big to small, it'll mess up the air flow.