Heat produces power so the more heat you can generate the more power you can get. My wife had a Buick station wagon that the first fan didn't come on till 238* and the second came on at 256*. Of course a lot of this was to meet emission standards. If your cooling system components can take the pressure run a <> 10# cap and throw the worries out the window. The qualifier here is you have oil that won't break down or clearances that won't seize.
