Here's a list of Chevy V-8 crankshaft casting numbers. Make sure your crank will work in the block you have. Blocks were made for each crank main journal size.
Cranks also use either a two piece rear main oil seal or a one piece rear main oil seal.
Rear oil seal adaptors are available from Chevy or aftermarket suppliers, if you are trying to put a crank designed for a two piece seal into a block made for a one piece seal. Mountain Time Mon.-Fri.