So, I was talking with my brother and dad about this and they really couldn't give me an answer. Considering that the XR650R/L engines are relativly similar, with similar bores/strokes.. I was wondering.. Would you ever be able to take an aircooled L head/cylinder and put it onto an R? Could you ever convert an L to watercooled by doing the opposite? I don't know, this probably sounds really dumb.. but who else am I gunna ask? Thanks for any/all answers.