Ok so i had the new muffler installed today. Well first i had thought it was 2.5"..I measured it too. the guy at the shop says its 2.25" and its not worth doing the 2.5" axleback. Ok... they install the muffler which i will post pics of but had much nicer welds and a rolled 4" tip instead of a regular 4" tip. The note became much deeper and also my engine response changed. W/o the 2.5" axleback i thought i wouldnt gain anything. But now besides being louder it seems to have more torque and more hp especially midrange and some top. I switched from a magnaflow to a powertech, i have never heard of them, but this muffler seems alot less restrictive. Now i did have an accident which damaged my last muffler so maybe something inside had been damaged. But honestly i cant account for this noticable change in response and even powerband from just changing the muffler...which is supposdly the same diamater. any ideas... the header goes on this weekend and i will definately have to put some dynamat in the trunk and some sort of resonator. any suggestions on resonators.