Well guys I bought a 4" In/out 14" case 20" long 7" round Magnaflow muffler from a friend of mine out of his Duramax exhaust kit, I was gonna do a full 4" exhaust but I've decided I'm just gonna put a 3.5" muffler in it. It is brand new still in the wrapper (don't have original box) I'm pretty sure it's even the polished one. I will post pics tomorrow when I get next to it again.
Online they seem to go for $123.00 plus shipping
How's $100 shipped OBO!!! or Ill trade for an oval 3.5 Magnaflow or borla