Hi,does anyone know what other rear shocks fit my 1990 gsxr400 apart from the standard ones.i was told all the 600-750 k series ones fit so i got a k4 one but could fit as the resivour hits the undertray.thanks kevin.

K6/7 shock is what you want, see my very recent post about the increased risk of tank slappers on rough tarmac. An old post here covers what you want to know. viewtopic.php?f=53&t=33439