Thank you, Mike, Gus, Jim, Cam, and Robert for your comments. Actually I am going to put new exhaust under her. She is able to run and drive now but needs interior, front grills and bumper installed. Thanks for the encouragement!!
Info on exhaust system enclosed. I'm running a 461 BBC; 10:1, Comp 292 cam, headers. Pypes system was a real bearcat to install. Neither of the up & overs were bent right. Ended up pie cutting and welding both of them. Drivers side was close, passenger side was not. I should have questioned the manufacturer as I noticed both were not bent the same but figured I'd get the run around. I wanted something quieter than the typical Flowmaster 40's sound. Originally I installed Pypes Street Pro mufflers. Sounded nice outside of the car but the interior drone at 40-45 mph with my combination was brutal. Like rattle the interior apart brutal. They lasted 2 months before I couldn't take it anymore. Ripped them off and installed Flowmaster 50's. These are longer than the Pypes mufflers making installation difficult but not impossible.
I used DynoMax Ulta-flow(welded) mufflers. I absolutely love the way it sounds. No drone at all. I checked the Pypes website( I think) for sound bites and specs before I decided. They have the best flow of all the muffs. Not to expensive either. Have had them on for 10 years or so now. No complaints.
regarding DynoMax Ulta-flow mufflers, they are just a glorified glass pack, but the packing is supposed to absorb interior drone noise, so you're saying they held up? my fearhas been after a while the packing burns out, Pypes just seem too loud and not sure on flowmaster for interior noise, there's another company making mufflers with rockwool instead of fiberglass not sure on that but it should last longer
From personal experience over the years. Flow master 50 no drone. Not loud but not quiet either. Pype's Street Pro sounded nice but drone was bad. Flow master 40's, loud and bad drone. Pype's Violater, totally loud and nasty drone.
My UltraFlo weldeds have held up perfectly and still after all these years no drone at any rpm. They have been running behind 2.5" Longbranches w/an X-pipe. And now behind the long tube Dougs and they sound awesome, IMHO. They don't sound anything like glass packs! I know after I bought mine they came out with something they called roving fiberglass packing but that may have been on their std turbo muffs.