So im ordering a magnaflow cat back system for my truck part # 16696, and id like to get a new Y-pipe as well and im not sure what one i need...the exhaust im getting is 3" piping, is it 2.5 at the Y pipe or 3"??? Also im not sure which style of Y-pipe i need, there are 2 styles on the web site....can anyone help?? Maybe a part number for me?? Thanks guys. 06 2500 mega-cab