Both you and I would whip the crap out of anything if it was just us to depend on it. I'm all about betting a nickle to a dollar if I have full control. Most boats die a slow or sudden death of pure neglect.
I wrote a few sentences about tearing it apart for inspection. If said boat owner was...
At 700 hours I would say the only things reusable are the block, crank and head castings. The rest is toast. Price it out.
I think a mild big block built with reliability from a donor with all the necessary parts would give that added top end bang for the buck.
700 hours was a good run.
I spent more on riding gear than I did for the bikes. It only took one time overshooting a razorback that ended up being a 40 foot cliff. Bike took most of the hit but I did jamb my thumb pretty good. I was so happy I spent the extra money for protection.