Check out Larry's Performance Shop 323-722-8865
www.larrysperformance.com
These guys quoted me a 383 shortblock with TRW forged piston and 10.1 compression fully assembled, balanced and blueprinted shipped to my work for $1400 and something. That is amazing! The 350 block I had was going to be $1500 for machine work (.30 over, decked, and cleared for the 400 crank) plus another $800-900 for a rotating assembly. Plus I would have had to put it together. Not exactly what I wanted to do for my first motor build was 383 and have to double check and triple check the clearance and grind down the block when I am just an amateur, but I wanted the stroker. They do all that work for you. I know that having them assemble it takes the fun out of the build, but hell no you know its done right. They do this day in, day out. I haven't made it to that point yet, so can't tell you if its a good motor, but you can't beat the price.
Also someone on this site has a new 571 Gm crate motor for sale. Yes I said 571. Its the 12.1 compression 720 hp 650 ft lb? motor. Only $15,000. But just remember, it has GM's warranty!!!!!!!!!!