I'd sell the truck for parts to @TonyP we'd all love to see what he'd do with it!
In all seriousness though, a 300k mile 200 with a blown engine and tranny isn't worth putting $10-20k into. The truck in perfect running shape is worth less than $20k for sure, probably only in the $15k range. Don't through good money after bad. I'd sell it and move on.
