Burkhart automotive in central NY has a 383 short block for sale. It's got a SCAT crank, forged 6" rods and forged pistons. This is a very reputable shop. They want $2,000 for it.
Shoot me an email jerryjfunk@krock.com or IM me if you're interested and I'll give you the number. I doubt they'll ship it, so you'd have to drive to Utica, NY.