am i going to see a big difference between using a resonator or a glasspack muffler to quiet the exhaust down in terms of performance or exhaust flow? Also thanks for the tips so far, i think i may now go, 2, 2" glasspacks into a y pipe, then a 2.5 " glasspack, to a high flow cat, and then to 2 dynomax or magnaflow mufflers, im looking to do a system real similar to mbtoloczko, you can check out his system in his locker http://www.subaru-svx.net/photos/user.php?mbtoloczko, thanks!