Awesome project!
I had a 3.0l engine of that vintage in my first boat, and it was a workhorse. I beat the snot out of it, and it never skipped a beat. Easy to work on, easy on gas, would move the 19' boat it was in just fine.
One time we were across the lake and the V-belt snapped. I made it all the way back to the boat launch - around 9 miles - without a water pump! Brought it home, put a V-Belt on it, put 50-100 hours on it for 4 more seasons before I sold it. Like I said, never skipped a beat.