I am starting on the exhaust on my Z and plan to run an x pipe with the new duals.I have read/found that the length of the head pipes from the header collector to the x pipe should be as even as possible,but no mention on the pipes length after the x.I can get them pretty damn close to even before the x,but with the way I have to go up over the axle the driver side x back pipe will be longer.Is this area for concern or just route the pipes aft of the x and don't worry?

 

The length before the X needs to be close to the same because of the exhaust pulses going through the X. You don't want different length pipes because then the pulses could possibly hit each other at the X, not good for flow. After the X doesn't matter nearly as much if at all. I read in an article once, not that the magazines tell the whole truth, but they ran all different types of dual exhaust on a ford 5.0, 400 hp or so, h, x, open headers, different sizes, and the one that made the most power and torque was a 2 1/2" off the headers, into an X pipe, 3" out of the X that expanded to 3 1/2" about 8-10" past the X into 3 1/2" mufflers. (or it could have reduced back down to 3" into 3" mufflers, I can't remember) It made like 2 less hp than open headers and more torque.