I've been looking for a thread on here that would solve the problem of replacing the rear shock on a SX with something upgraded from the original. I found a thread that had a vague suggestion with added parts to make it work.
I replaced the rear shock with a '93-'00 TRX300 rear shock and it needed no mods. Bolted right up with the original hardware and no spacers or dowels. I hope this helps anyone who was thinking of upgrading or replacing.