I know Scott(dizuster) made about 470 RWhp with his stock block 360 with a turbo... he was driving right through the conv with 18% slippage on the dyno... I'm not sure if he even changed the pistons to lower the compression any farther than the low compression it already had... and he didnt even have the boost up much at all... and you cant even hear that car running.. thats the trick part about turbos