Water down the carb works good to steam clean the top of that piston..

IMO, your pushing the laws of physics. You're turning that little blower at nearly 13,000RPM now. Forget about the whole theory of "its ok at 6psi, or its gonna blow at 8psi". You bet your azz 8psi with a 10% underdriven blower is gonna be a hell of a lot safer than 6psi on a 140% overdriven mini roots. The heat generated by the gas law (pressurizing air naturally heats it), is minimal compared to the heat generated by that little blower. This is why we intercool to run more boost. Lower the temp in the manifold and you can run more boost. Even with a superchiller, I'll bet your IAT temps are getting up there. Suck up some crap in the chiller or feed to the chiller, and its gonna be game over in a hurry.

If your liking the power gains from boost, invest in a larger blower. 8-71, 420 B&M, etc. That 174 was designed to do about 5-6psi on a tow truck engine or a mild street engine, not a marine high performance offshore engine.

Thanks MT, I have begun thinking that way already knowing that I have reached the end of the line with my set up. For the most part I keep in under 3800pm (cruising 3400) but I know it will only take so many WOT before I have an issue. Not to mention 2 carbs look better then 1! I have to figure how to post some pics. The engine and boat look great this year.