450-475 HP?? A cast crank can handle that. The only reason it would destroy itself in a year is if the machining was wrong or the assembly prep.

Once you price stuff, the new crank, forged pistons & etc., it's either go KB's w/cast crank and prep'd factory LY rods or the stroker big block kit as mentioned.

If you must have a forged crank, there's always some in the Moparts Classifieds.