I agree, Steve's idea is very sound since cooling the charge air is a key component to increasing HP. The phenolic spacer concept is much the same, what I can surmise is that it isolates / insulates the SC outlets from the engine block to limit heat transfer to the SC housing material and thus prevents transferring that added heat to the charge air.

And of course, cooling an engine is a good thing... But, slapping on a less restrictive thermostat is not going to increase your HP unless you're engine is running seriously hot and the new thermo reduces the heat substantially... I just get ticked when I see unsubstantiated claims and there is no data to back it up... I know exactly what the ECT's run on this engine because I have logged them electronically... And to make claims that your new whiz bang gizmo reduces engine temps by "X" amount and not have ECT logs to back-up your claim, is typical used car salesman stuff...

And, for that matter, if you are so worried about ECT's and want to reduce them, remove the damned thermo completely to get a free flowing cooling system... So what, it will take you 5 minutes longer to get your heater to blow hot air !!! We don't run thermos in engines, no need...

Get the point ?