Re: transom-motor bolts
No, Just use lock nuts and washers and make 'em tight. You do not want to compress the transom.
BTW - I was testing my Fat-fifty on my 16' runabout one saturday morning. The transom bolts had not yet been installed. I hit bottom and the motor popped off the transom, snapping the electrical, fuel, steering and contol cables and sunk to the bottom of the creek. It hit the salt water running at planing speed, and was under water for 60 hours. I recovered it, hosed it off, cleaned the starter and dissy, and poured fresh fuel thru the cankcase, to remove the sand, salt and weeds. It started and ran fine, after that.
Don't forget the transom bolts!