Just finished installing x-pipe exhaust on 72 El Camino. used a Torque Tech kit with DynoMax mufflers-3 1/2" pipe from headers to x-pipe then 3" out of x-pipe thru mufflers and tail pipes. Once my son figured out how to do it was a simple straight forward install. We welded all the joints except for the in pipe to the mufflers and the tail pipes, if these leak once car is started then will weld them. I also used a Torque Tech kit om my 72 Monte Carlo and it was very easy, just a regular dual install. Highly recommend them. Still have some things to do before starting it up, will have to get a little warmer here in Fort Worth before that occurs.
D.R. Jones 72 El Camino 72 Monte Carlo 59 Cadillac 44 B Farmall 68 250cc MW Touring
