Go to autozone, adv. Auto Parts. They have kits for all the piping for $88.00, then all you need is a muffler, clamps and hangers.
That is without a y-pipe and without cats.
Really? Huh. We went to autozone and they punched it in their computer and all the piping was 88 bucks for an 84 el camino. Im sorry i dont have a link.
Pipe size depends on what motor you are running, if you have a 305 or other small displacement V8 or v6 I would go with 2.25 - if you have a 350 I like 2.5.i called the other Autozone here locally and they said they could special order it and 2.25 was like $102 and 2.50 was like $199, What size do i need and what length of glasspack should i get ?