I had an aftermarket Ohlins shock from a 1996-97 KX 125 on my 2000 300. It was a slightly different length but the different length pull rods (shorter if I remember correctly) brought it back to the correct ride height. I liked that setup better than stock as it seemed to be much more controlled and more plush at the same time. I removed that setup when the bike sold so PM me for more info if you want to see some pictures. On a final note, I fit a 1999 KX 250 shock in the frame/linkage and it also fit but I did not measure for proper pull rod length nor for exhaust clearance.