Being a 71, it "should" be a strong boat!!....Hullwise.
...and your right, also being a 71 will make it harder to get advice from the manufacturer.
...what would I do?.....
I start a post here, asking for suggestions, give details about hull, size, construction....and of course the specs. on the outdrive you wish to mount.....
.....I'd put it on this thread, as well as start another thread. I'd also put it on the other site......in as many places as possible, for example, the Main, the Mass., the Tavern, the Boating.....etc....
......people seem to be very helpful on these sites....
...sorry I couldn't help you more...