Re: Is '68 9.5 hp a good donor motor for a '64 9.5?
The 1968 cowls are different top and bottom, having the latch located opposite.
The propshaft seals are different, but most other parts are the same and the gearcases will swap.
The lean/rich needles and packing are different but the carburetors can be swapped.
The 1968 has improved suspension system which you may prefer to use.