I have had the same boat and motor since 1986. Been through many winters and expect it to go through a few more.
It is a 1985 Almar JetStream with a 351 Ford motor and Hamilton 3 stage jet. I know nothing of winterizing outboards.
1.Open all drains and leave open: Sand trap, manifolds, heat exchanger, hoses.
2. Check anti freeze quality in block. Should be good to 35 to 40 below 0.
this should take care of all freeze up problems.
3. Pull batteries out of boat and store in garage. Set them on block of wood instead of on concrete floor. Check fluid and charge every 2 months.
4.Fill fuel tanks with fresh fuel and add Stabil to each tank.
5.Pull carburetor off of manifold and store inside. After removing--loosen bowl screws and drain all fuel out. Set on bench for a couple of days with bowls disconnected to allow evaporation of fuel left inside. Spray outside and inside with WD40 and insert in plastic bag. Place on shelf till next spring.
6.Pull spark plugs and spray engine fogging oil into each cylinder. Reinsert plugs and crank engine over a couple of times to coat inside of cylinders.
That is about all I do each fall and I can usually count on the boat being in tip top shape come spring. After reading this over, I guess you should exchange the order of #6 with #3. Guess your gonna need the batteries still in the boat to turn it over for fogging.
Last but not least -- I always make sure the interior is as dry as possible before tarping up boat for the winter. Any wet floorboards or what ever run the risk of freezing and splitting or splintering, or at the least rotting to some degree over the winter.