BluePrint Engines? Experience?

If that's all your planning on making a cast crank is fine. Cast is rated to 500 hp. Mines around 450-460 with a cast crank and I've been beating on it nearly 2 yrs. and is holding up fine. If it comes down to a forged crank not costing much more I'd do it just as a measure of safety, but most likely it'll cost quite a bit more.