Take a stock LS1, bore it plus .010", add ARP bolts/studs to the stock rods, mains and heads, put forged pistons in it with increased pocket sizes in the pistons to drop compression or add 317 casting 6.0L heads to drop the compression. Run 10+ lbs of boost and you'll be easily 500+ hp at the rears. Talk to Billy or Allen and they can put you together a game plan.