I had to pull my 454 out cause I wiped 2 lopes off my Comp cam, In the process It wiped out my crankshaft and bearings, Since I have to replace the crank, I was wandering if I could just drop in the Scat 9000 series crank with a 4.25 stroke for the 6.135 rod without any modifications? I have good steel rods and forged pistons that are already balanced and don't want to replace them, thanks david

you'll need pistons for the 4.25 stroke.

You do not have to replace the crank, turn it. .030 under is not an issue. You're balance will still be OK, and it would be the cheapest way to repair the motor.

If you WANT to stroke it,
you CAN replace just the crank and pistons and use stock length rods.
It will cost you more in balancing than it is worth though.
The short rods keep the pistons wrist pin are closer to the crank counterweights. So the counterweights must be designed for the short rod setup, smaller in diameter.
THsi equates to not enough counterweight, so you must use Mallory metal. It gets expensive. Your $275 crank becomes a $800 piece before you are done.

Your best bet if you stroke it is to buy a forged 4.250 crank, and some 6.385 rods, and the correct pistons.
This will get you balanced easier, be a better combo from a cylinder bore wear standpoint, and generally less hassle.