Most of them are basically glass packs, so they should sound similar. Glass packs are only restrictive if they have a poor design with a louvered center pipe. If they are punched, they have far less restriction. I have heard import mufflers that sounded great, and those that sounded like sh*t. Generally, the better brands like Apex, etc. are better made and have a nicer sound to them. Cheap stuff like APC tends to be the bad sounding stuff. As for putting them on a musclecar, the vehicle's architecture generally works against that. Remember, your typical subcompact has it's muffler there stock, so it is designed with enough room for it to be there. The typical musclecar is designed for the mufflers to be under the back seat, or between the axle and gas tank. What I would like to try is putting two mufflers under the seats, but then having two (or one with 2 in, 2 out) in the behind the axle cross over position. If you used free flowing enough mufflers, it would make for a very quiet car that gives up little in the way of power. Very nice for a sleeper, or to keep pesky cops from harassing you.
