My ‘72 350 has turbo mufflers that are about 20 years old, with about 20k miles on them. Now that I’m older and the mufflers are too I’d like to get a quieter exhaust tone. I’d like to get some ideas as to whether I should add resonators to quite down the existing exhaust or is there a quite, free flowing muffler that would be better? At 72, I’ve aged out of hearing loud exhaust cruising down the highway but I still like a nice rumble at idle.