Hey guys. Curious about what will fit exhaust wise on this 02 YZ 426. I hear some people saying up to 05 450 fits and others only 426. Also GT Thunder. Does anyone know what they offer for the 426? This bike has a new jug with GT Thunder sticker and a spacer between the cases and jugs. IM also told it has a brand new crank. Enough of a spacer that the stock timing chain will not fit, even with no tensioner and the cams not bolted in. I am out of the country and cannot call GT that's the only reason I ask. I believe it has a new Weisco piston, I'll try to get a camera down the plug hole to get the numbers off it. If it is a big bore or Stroker of some kind id imagine I'm going to have to richer it up abit, specially if I go with a full exh system. Thanks for the time and space guys.