When we modify our 4x4s for off-road use, sometimes parts of the exhaust need to be changed or moved so everything will fit. Solid-axle swaps are one major modification to lots of systems on a 4x4, and the exhaust is one of them. When we did an SAS on our 2005 Chevy Tahoe, Rosco P. Drivetrain, we had to make room for the front driveshaft. That meant cutting up the factory Y-pipe to rotate and move one of the pre-cats, and then adding a new crossover pipe. By cutting at the arrows and tuning how the tubes butt together, we were able to get the Y-pipe back together without reinventing the wheel or adding a ton of new parts. The only new parts were the exhaust flange donuts and the shiny section of 2 1/4-inch tube for the crossover.