Re: year ?
You can look up the year with the serial number and the HP at maxrules.com. Since you do not know the HP, you need to do some dectective work.
Make some guesses as to the HP, then look up the year by serial number. Now get on crowleymarine.com and look up the block part number. If your block part number matches,you have figured it out.
I would start with 115HP, since that is probably the most popular HP in an inline six. It could also be a 90HP. If it is a sixties motor HP could be 85
