My buddy is trying to recreate my exhaust system on his car. He bought a MAC 2 1/2" o/r H Pipe and a set of Flowtech Longtubes, 1 5/8" Primary w/ 3" collectors and 2 1/2" reducers. He wasn't listening well and ordered the wrong stuff. The 3" collector comewith a 3 bolt flange. The H-Pipe has a 2...