Up to 10 HP power increase for the older models from 1976-1980 with 99mm block bore - just exchange Cylinders+pistons - nothing else has to be modified. Kit includes new Nikasil cylinders with stainless steel pushrod tubes, lightweight 9.5:1 1000cc pistons modified for your existing combustion chamber, wrist pins, rings and circlips.
Kit is complete except for top end gaskets.