Hi Fred,I have experimented with cross over pipes on my old British cycles, yes they are 2 cylinder inlines so to speak,lol.
The cross over was good for bringing back mid range power that was lost to a radical cam.A slight loss at maximum RPM's,no big deal.It also makes carb tuning easier ,again,my opinion.
On the several inlines I have modified,a 261 Chevy and the recent 302 GMC,I run what some call a tri Y header(2 into 1) with a large single pipe and muffler.I'm convinced this set up adds throttle response and power at normal road speeds with no loss at higher speeds.And to me,the large single pipe gives a smooth ripping sound rather than the rough sound of duals on a 6 which sounds like a V-8 with dead cylinder to my ears.
