I did some research, and found that WR250F axle blocks fit a WR250X. These blocks were half the price of any others, and the quality is very good. I used the lines to adjust my chain, then tested with a tape, and sighted down the chain, they seem to be accurate.I wanted aftermarket blocks to run a longer chain for future gearing changes. The ONLY thing I would have liked better was a deeper red anodizing, it is just a little light. I would buy these again.