Other then stainless head gaskets, brass freeze plugs, and cam they are the same as a standard vortech engine. Engine castings, crank, rods, and pistons arent anything special. You could go with a direct marine replacement for a simple fix or buy something with more stout components from summit racing. They typically sell engines with 4bolt mains, steel cranks, forged pistons for slightly more than the marine basic replacement engine. Heres a couple to consider:
Gm vortech:
http://www.summitracing.com/parts/na...0282/overview/
Or 383 stroker!:
http://www.summitracing.com/parts/ml...make/chevrolet