picking the older or newer engine

have a 1976 Johnson 70 HP rebuilt once before on 15 fiberglass trihull
and 1988 Johnson 50 hp with jackplate power trim/tilt on 17 aluminum jonboat
hull conditions probably ok but trailers, wheels probably shot
engines were performing good before but both sitting up for at least 10 years
doubtful if either fogged/prepped for storage
plan to get mobile OMC repair guy to check out engines before i do anything else
1/ what field inspections/tests could he/should he be able to run to help me chose go/no go?
what would be reasonable cost for doing both engines?
2/ if equal, which might be better keeper choice? older 70 or newer 55?
Boats inside fenced backyard
3/would it be more practical to remove from boat go directly to shop or upgrade trailer and move?
I am flexible, want to get value out of these but do not want to throw good money down the drain.
thanks
wgaboy
Georgia

Re: picking the older or newer engine

I can only speak specifically about the 70 HP as I have a 1976 70 HP myself. I rebuilt it 10 years ago after buying it way back in 1992, and it just goes and goes and still has almost perfect compression after many, many hours. I don't think you can find a better motor in that HP range, and I wouldn't be scared off by the age of it if everything checks out OK mechanically. Plus, I think you'll come to appreciate the extra 15 HP as there really is no substitute for the extra power.