Well dang, hadn't thought of it that way. I guess the flip side is - when the fan is not running, the air flow through might be better. The holey shroud theory is probably right up there with those people who swap out a 190° thermostat for a 180° unit thinking it'll run cooler. The thermostat opens sooner but max cooling is not improved. Oddly enough, the only time my temp light ever came on was when I was on the freeway - doing about 70mph, slightly down hill so not at full throttle. I think the stock fueling is lean at less than full throttle. On the other hand, I've pulled long inclines WFO and the temp stayed in the good range. I have one of those cheesy radiator cap thermometers to help me worry about engine temp.