need exhaust measurement

Long story kept short I got a 76 had no exhaust I got a excellent condition original resonator and muffler off of a 2+2 but need to get a new pipe bent and I need help with clearences so I don't get pipe bent wrong. It looks like the 2+2 pipe is the same but too long in some places. One question is how far behind the crossmember that goes behind the diff should the pipe be? That is right where it bends up. If you can help that would be great or if anybody could e-mail me with pics of a stock exhaust to show clearaces mainly from Muffler to Resonator. Thanks Jim