sorry but id say keep the x on there,lol....seriously your car is gonna sound blatty with the o/r h....but ive been in this situation before, at first i planned on cutting m UPR X like yours but then when i purchased the longtubes i decided to get the o/r prochamber to tame my exhaust a bit...was running o/r x and borla stingers at the time...well, the prochamber tamed it alright, so much my car sounded constipated,lol....i didnt like it at all....so i had already sold my upr x, so i had to purchase a vrs x for longtubes and finally sold the prochamber this week...id say save money and modify the mrt h or keep your current setup with the x pipe.