Cross-flow muffler?

[jst8a5.0]

I really hate to be the guy with the bad review, BUT my dad has a 69 firebird with 455 and i have a 74 Ventura and we bought flowmaster exhausts at the same time. I have a 400 with comparable mods. I got the system with the two 40 series and he got the crossflow. Almost on a daily basis, I would get run off the road by someone telling me how much they liked my exhaust note. On the other hand, my dad was almost embarrassed by the sound his made. Both cars have headers and 2.5" pipes. As soon as he switched to 3" and magnaflows, he had a lot more power and better sound. His car runs 11.18 and looks nearly stock. Maybe just doesn't sound good on Pontiacs? Oh and fit was great, though. Plenty of ground clearance.