RE: K&B .28 piston scoring
You say that engine sat in the Everglades, submerged, for a few years? I've never seen a crankshaft in that condition before. Fortunately, they are still available. While you're at it, pick up a few crankcases with the bushings installed. That will save you some aggravation later on. I think I'll take my own advice and order a couple of .28 and one .65 sized crankcases myself.
I've been thinking of buying a couple of Davis Diesel conversion heads. That's why the concern for bushed crankcases.
Ed Cregger