440 crankshaft questions.... Pic included

What year is the engine? Is your engine assembled from parts from various sources? Do you trust the person who told you it was a cast crank?

See this page to help identify the stock damper (balancer) you may currently have: http://www.440source.com/dampers.htm

If you have the balancer that was on this crank when the engine was disassembled, it will be starting point to help determine what you actually have for a crank.