I have run the cast Scat at 750+HP, but I would not recommend it. One of the only ones I had break was at +/-716HP, and it was at #1 rod.
Probably draw the "line" somewhere below that level.
I have had a couple RPM cranks fail. Some of them were very thin around the lightening holes in the rod journals.
The Scat steel is decidedly better in that respect.
I would recommend steel in anything running a belt driven blower due to the long FE snout, and the leverage at the pulley end.
I also steer toward steel in anything with a high cycle time such as endurance, extended marine use, or road race stuff.
Since you're on here, Barry, I'm starting the Frankenstein 428 with the "holy" Eagle crank I bought from you a while back.
It internally balanced nicely, but man, it sure has a lot of lightening holes drilled into it! Swiss cheese!
