Any six horse powerhead from ’65 thru ’79 will be a direct bolt on. Driveshaft splines are the same, starters are the same, water passages are the same etc. The only major difference is in the ’77 – ’79 models which have Capacitor Discharge ignition instead of points style magneto systems.
I don’t know why but piston scoring seems to be a common problem with these motors. Could be from wrong fuel mix, old fuel, overheating or any other thing. Where abouts are you located as I have at least a half dozen running and tested powerheads sitting on the shelf waiting for a new home.
