This is probably a dumb question, but if you have tuned Long Tubes (I have SLPs), why do you still need the X or the H pipe? Is it just to balance back pressure, and if the tuned LTs are scavenging the exhaust, is balancing important anymore? My Loudmouth I pipe splits just over the axle to dual slash tips. I was thinking of having another I pipe bent to lead from where the I collector is now, and slapping a pair of the LM II modular resonators in line. The current original LM has just a resonator, but I don't think it's the same as the new modular one for the LM II's, so I'd buy a pair of the new ones, so they're the same on both sides... See the pic attached.
BTW - my clearance is aleady screwed by the SLP LT collectors