thanks thats very helpfull.as i live in england and we use the cat system.does your spec sheet also tell you what year they go up to or if they are also fitted to the non carb ones.the reason i ask is my standard taperd run fine but i like standard pipes and the slashcuts i put on pop a bit just of tick over say 3,ooo revs is this the norm,just trying to find out why slash cut standard seem to pop crackle on the over run and tapered dont. That is why i asked if they were compatible.Any way many thanks for looking it up for me.