Hi Waverider,
As both Mod CyberJack and DeeJay have eluded to that your engines output PTO shaft is quite serviceable and no need to worry about the wear factor on the key way. This is because the new design of clutch half is designed some what different to the earlier units that used the sliding cotter pin to clamp against the shaft while the new ones use two set screws to actually pin the the clutch to the shaft at 90 degrees to each other thus there will be no clutch movement on the shaft and the key steel is also pinned to the shaft, again no movement.
In the end all will be better than original.
Cheers,
BB
