Re: New to iboats
Hey, welcome aboard you old yellowjacket!

It's never a good idea to exceed the manufacturer's specs. Even if you beefed up the transom there would be other considerations. Everything on that boat; hull design, number of rivets/welds, etc. etc. etc. was meant for 90 horses or fewer. Using more could compromise your hull.
Then, there are the legal implications. Here in the natural state we're required to insure any boat powered with a motor larger than 50 hp. What would your agent's reaction be if you told him/her you wanted to insure your overpowered boat? Worse yet, what would be the reaction of the plaintiff or plaintiffs' attorneys and the insurance companies if you had an accident in said overpowered boat? You'd risk losing everything.
And finally, there are the moral implications. You'd be compromising the safety of anyone aboard and anyone around you on the water. Could you live with yourself if something happened? Would something happen? Probably not, but if it did you'd be SOL.
Not worth the risk IMHO. But, my advice is worth what you're paying for it. Sorry to be such a downer, but it's always nice to run into a fellow Arkie on here.