I'm installing a true 'X' pipe with dual 2 1/2" to the back into a single Magnaflow SS muffler (5x8) that has dual 2 1/2" in and single 3" out.
That goes in next Tuesday, June 22nd, so I should have an idea by this time next week what the sound is like. Savage 42 heard an sbc Z set up similarly to this with dual 2" into a 2 1/2" out and thought it sounded really nice. We'll see.