Cast Steel ? Ya that crank is in most regards about the same exact strength of a SCAT crank.
Its never horse power that breaks things anyhow.
I can tell ya many stories but... I'll tell my favorite crank story.
My father owned a 390 flatbed. And we overloaded that thing every day... finally after 1 job... the crank broke, and all hellish nooises you can imagine were happening.
But the strangest thing is, we drove it home!
When we pulled the block apart.. the crank broke into 3 pieces, and each break was the perfect wedge, to continue to make the crank spin.
Parts break from abuse