Should there be any play in the prop shaft assembly? My 67 K&B has some and doesnt seem right. You don't run a sloppy prop shaft on an inboards strut so why would there be on an outboard unless it's worn.....my thinking anyway.
I've run lots of 7.5/11cc K&Bs with some slop in the stub shaft. It's not ideal, but it's not the end of the world either. If it gets really wobbly, it should probably be replaced.