The instructions state to remove the muffler and tailpipe in order to mount the rear upper arms. It was easier to just pull the remaining exhaust out. Due to the passenger-side upper arm going through the area previously occupied by the muffler changes needed to be made. We got a Flowmaster Hushpower muffler along with some straight and mandrel-bent tubing from Summit Racing. Using the company's tubing expander tool we cut and welded until we had an exhaust that cleared all the new suspension.