Stuck pistons/Crank, any ideas?

I procured a 383 engine (sans head/intake) from a friend. I got the oil pan off, timing chain and all that. I removed the 5 main caps and bearings as well as the main seal bridge with no trouble. I am trying to unbolt the pistons from the bottom but cannot reach all the nuts unless I can turn the crank but it won't turn. The block is on my garage floor. I have no way to get it up to the engine stand or transport it anywhere at this time. There is some rust and the motor sat a while but the crank looks great. Any idea how to move the crank and or bust loose the pistons? I am going to look for an angled half inch wrench that might fit in the tight spaces. Any ideas will be appreciated.