My 73 has a 383 engine with a little bit of cam in it, 230 duration 480 lift cam, long tube headers, a new 2 1/2" full exhaust with X pipe, and an old pair of Cherry Bomb turbo mufflers. I have used sound prevention and heat insulation material on the floors and roof. On the highway the car is still too loud inside to cruise long distances comfortably. A lot of it is wind noise I know. I would like it a bit quieter. I dont know if the Cherry Bombs are the entire cause, if changing to different mufflers will help? Adding resonators? Just would prefer not to totally restrict it if possible.