Re: 1956 5.5 Fisherman
That is a nice find and a good project. Looks to be in very nice shape. I bet you will find that there isn't much to do on that motor. I see the fuel lines have been replaced along with the plug wires. I suspect its had a complete tune-up somewhere in the not too distant past.
You should clean and set the points again anyway so you can get a look at the coils then. You will need an impeller. As well, there is an assembly that sits on top of the driveshaft and makes up the lower crankcase seal. When you remove the powerhead to replace the impeller, change out the cork gasket and o-ring that are part of the assembly. Attached is a blow up of the seal assembly. The part numbers you will need are listed below.
1) Cork gasket BRP 303355 (Sierra 18-2892)
3) O-ring BRP 303347 (Sierra 18-7180)