What are you looking for exactly?

I am looking to upgrade to the same, or similar set up that you are.

My boat has twin 350 Mags (260 hp), I am under the impression with the Vortec heads and RPM intake I should be able to make close to 320-330'ish hp.

To truly optimize the engine and take advantage of the heads, you need to upgrade the cam. But, according to my machinist, he said 320 ish is common with an upgrade like this. I'd love to see actual numbers from a dyno though.

Well, dropped off the block to the machinist. He said that I need to go .030 over, because of some cylinder wall scoring. Looks like the pocket is already getting drained!!