This listing is for a complete SOHC Exhaust valve lifter set consisting of: Eccentric valve lifter spindle, Valve lifter arm and bolt, and the volute spring. As a kit, this can be fitted to any SOHC cambox that employs a machined and sleeved boss on the cambox backplate casting to take the exhaust valve mechanism. Note: most racing cambox backplates did not have this boss (in which case - sorry to say there is no point buying this kit), but some racing backplates used the casting with the boss, but did not machine it. This type can be bored quite easily and a simple shouldered bush fitted to allow the exhaust lifter mechanism to be fitted - email us if you need more detail. CS1 camboxs used the same mechanism on the boss, but the cable was fitted to the front leg of the cambox shell.