[nxtruck]

I concur. Even though I've had good luck with my current motor (509-based 434), if you're planning on making 600 or more, you may want to consider upgrading to an SHP. I've ran a few 509-based motors ( 3 377s, a 421, and my current 434 ) and split the #4 cylinder on one of the 377s with some nitrous. If you just looking for a 500 or so hp bracket motor, I say run the factory crank, a set of cheap 5.7 rods, and a set of budget forged pistons and have at it.