factory 340 forged crank

Always some confusion on billet cranks, too. Billet cranks are carved out of a steel billet much like the raw billets that forged cranks are made of.

Cast steel cranks are just that cast in a mold at a foundry then machined.

If you look at other videos showing the machining process that a quality crankshaft goes thru you will see the difference between a 'good enough' import piece and a high grade crankshaft.

Back when I was hauling a lot of auto parts from '98 until the early 2000's I did a few Lunati runs where I picked up raw forgings from the supplier in the Detroit area and took them to the heat treat facility in Lansing, MI. From there they went to Lunati for final finishing. I had a hard time not grabbing a crank or two that didn't pass the heat treat test... they were dumped in the scrap bin to go back and start from scratch.