\'83 Exhaust Legal Loop Holes----FOUND! (Kinda) What year did it become mandatory to HAVE to run the single pipe and one cat setup on trucks. Every exhaust shop in town is telling me I have to do that way before I can even get out what year it is to them. I have a cheeseball homemade dual setup at the moment with brand dynomax super turbos. It would be really nice to able to use those mufflers on nice pipes instead of having to be out the money for those mufflers. Not to mention how much easier transmission work is without a stupid crossover right in the way. I have some wierdo stainless steel tubular manifolds that GM used for a very short time on heavy duty applications. So the dynomax tubing kit wouldn't work. Heck I'd be even happy with true duals with a cat on each pipe. I always get the routine that it is HAS to be a single pipe. Does anyone know what the laws are on this and what options I'd have.