just wanted to add, if you guys are looking for 4" mufflers with a 4" inlet that is super hi flow this vibrant muffler i got sounds unreal! it is very loud but super deep. ive seen a couple threads and posts on guys looking for mufflers for custom setups with 4" inlet and didnt find much. it was this or the aes mufflers so i chose the vibrant as not many poeple do. just to be different glad i did sounds way better than the hks,tomei, or kakimoto gt1 oz(in my opinion). althought we have no laws down here at all for exhaust so might not be the best setup for places with stricter emission laws etc.