A friend has a 2013 Boss and he wants to buy ARH headers with off road X-pipe. Currently the car has a full Magnaflow exhaust from the cats to the mufflers. Here is a link to exactly what he has, Magnaflow Mustang Competition Cat-Back Exhaust w/ X-Pipe 15166 (12-13 BOSS 302) . Question, will the ARH mid pipe slip fit with the Magnaflow over axle pipes????