Thinking of exhaust mod
I had headers and true 2.5" duals out the back with Dynomax Ultra Flow mufflers. It was so loud at even cruise you had a hard time carrying out a conversation. I had an H-pipe installed (cost me less then $20) and it was night and day difference. It is still plenty loud especially when you get on it, but now you can talk without yelling. A crossover pipe of any kind will reduce the volume some, and help it breathe better, but it certainly isn't needed in all circumstances....just my $0.02