Finally got my 80's series flowmaster installed. Sounds incredible. Lost the resonator, but stayed with factory 2.50in pipes. This is the way to go. The installer also custom fabricated inlet and outlet pipes and custom tips. At idle it sounds like a mustang, but at 3000-5000 rpm it sounds like a lambo.....It was the first FX he had ever done but has a lot of experience with German and Italian cars and said he was actually surpised at how our V8 could be messed around with a little to sound incredible. My suggestion is stay stock with the pipes, its cheaper and the performance is better.