I would be doubtful of any engine, especially a virgin one, thats been on the shelves for 20, 25 or 30 years. Gaskets go bad, internal corrosion, prelube must be chevied (like a rock) by now...and did any critters make it inside through the intakes (they don't look sealed in the pics)? etc.
It has the +++ that it has new castings not subject to previous metal fatigue or stress, but I would be nervous about it, especially at start-up. I would probably tear it down just to be sure...but thats me.
Even as a Box O Parts, (new parts) it may be a good deal...the cost of a new crank, rods, heads, case, they all add up...MMMMM