theres not much benefit to removing the A.I.R. system.. it uses very little horsepower and you may need it for emission inspections.. best to check local laws.. true duals will add a little performance and much better sound
save money by going to your local muffler shop and have them fab up a true dual set-up with 2 1/2 inch .. get a set of Flowmasters or what I run..Ultra-Flows and eliminate the cat.. it still won t be fast, but it will sound good
Of course they can but that is not what they normally do. If you want one made with bolted up joints it is going to cost more and you will do better with a prefab cat back system which is not expensive depending on the supplier......a muffler shop can easily make a slip fit connection after the holes in the x-member of pre-80 models [ 80-82 did not go thru x-member]for easy removal of either front or rear sections, and mufflers are still removable as well... they do not just weld everything together..and will cost less than 1/2 of a prefab and guaranteed to fit right ..A C3 is a very simple exhaust design unlike later generations..
75-82 exhaust systems are not dual systems. They join into a single pipe before the CAT and then in the CAT back part they go out to each muffler, so there is no use for a x tube......What about putting in an X tube to balance out the exhaust gases?