My 71 has hooker supercomp long tube headers, the summit brand 2.5” exhaust, and thrush mufflers. First off the sound is very muddy to me. The headers hang down far too long and run into the steering linkage pretty bad. Also, the person who installed them before I owned the car welded it up like crap and it interferes with the leaf spring on one side. Planning on TTI 1-7/8 headers, TTI 3” H pipe, TTI tips, and still debating on mufflers! The pypes street pros sounded great in all the videos I watched.