The chassis that the 1972 Ranchero GT with the 429 thunder jet engine's? What other chassis shared the same motors and other models with dual exhaust with cast-iron exhaust manifolds. I have a 429 ranchero gt and a H-Pipe from a 1970/1971 Torino that was for a 429 thunder-jet the H-Pipe has a 2.25 inch OD that would connect to my cast-iron exhaust as the down pipes but I don't know what other combination of pipes and mufflers and over the axle tail pipes to use to bring the exhaust tail pipes to the rear bumper and exit the exhaust that way. It would help to know what other chassis years and model's with the 429 to order the dual exhaust system and fit the 1972 Ranchero GT model. Thank you Larry