I had the exhaust done on my 760. It is dual 2 1/2 back behind the transmission then crosses over and goes into a flowmaster y, 2 1/2 into single 3inch, which goes over the axle and then into a flowmaster 3inch single in, dual 2 1/2" outlet, and exits both in the stock location. I would not reccommend any flowmaster muffler, because they are loud and create a lot of interior resonance. I would go with a dynomax, or magnaflow. All together including a cat, muffler, y and the pipe and install, it ran me 400 bucks.