Well due to some misfourtune and stupid mistakes I lost the case drain plug and ran my bike without oil. The engine started to seize when I killed it coasting down a trail. The bike is a 99 400 I tore into it and found most everything in the head to be OK. There is slight wear on all the cam sprocket teeth but all the lobes check out. The head and valves appear to be in good shape too. As for the piston and cylinder, they're toast. The piston was badly scored and the cylinder isn't pretty either. Due to the lack of lubrication the crank did blue a little bit but the bottome end from what I can see looks to be in good shape too. The rod looks OK. The crank bearings look OK too, it turns over smoothly. Is a blued crank cause enough to replace the crank and everything else in the bottom end? As for the piston and cylinder if I could leave the bottom alone I think I'd probably just do the 420 kit. I know that I'd like to go with the 426 parts if I have to split the cases.