Stuck pistons/Crank, any ideas?

I had the same problem with a 383 also,but all the piston rings weren`t froze, just the cylinders with intake valves opened. 1st don`t get in a hurry. I rolled it on a piece of plywood to protec the floor.Rolled the block so the cylinders were straight up.Soaked the cylinders w/ brake fluid for a couple days then kerosyne for awhile then w-4o. Kept flipping the block from one side to the other chock it so it stays straight up..Cut a piece of 3/8th plate steel same diameter crank flange,drilled holes to match the flange,welded a 1-3/4 nut to it,( don`t use hamonic balencer bolt to turn the crank) used 3/4 in. breaker bar and 1-3/4 socket w/ a 4ft. cheeter pipe.Just keep working it..Once it starts to move just a little,you got it made! Depending on how bad it is you may want to soak it some more...Don`t use a-lot of force,,you may bend some rods... Use someone to help keep the block from flipping over..