My wg pipe is 2.5 inch/63mm, so it might be a bit tighter than yours. I'd already hammered the fark out of the dump years ago to get clearance. I have a 3 piece dump, one small bit from the turbo (3 inch) to the 4 inch top part (90 degree), then there is a second lower part that has the wg tube receiver (also 90), then the cat goes onto that, then intermediate muffler section, then up section, then the over the cradle section, then rear section with resonator. It's all vbands and can be difficult to line up perfectly the first or even third try. Just gotta put it together and adjust it as needed. Nothing is banging or rubbing now so we'll see how long that lasts.