I am currently rebuilding a 88 yz250 bored out to 270. I bought a whole new top end and I am about to buy a new crank and rod. My question is, when the the bike detonated the bottom end must have been VERY hot, because most of the bearings in the trans side are toast. The ones I am talking about are the largest besides the crank bearings and have a plastic sleeve covering the bearings themselves. I am looking for a diagram so I know which bearings I need to buy, or where to buy them. Also is there a thread with compatibility listings of parts on these older yz's? If there is it would be very helpful. Any help is appreciated, -Thanks, Louis.