ProSport, they will get loud pretty quickly as the center blanket will break down & leave the mufflers. With 3" exhaust, it's hard to quiet-down the exhaust without resonators. I build 3" core resonators that are 4" round body, & I use packing that will NOT break down & leave the mufflers. I can also build them in any length. If your 3" system is too loud, consider adding resonators - they will not hurt performance or restrict flow.