FYI, in case anyone out there is interested who has expressed doubts about the temperature ratings of 12 Volt computer fans of the 6.5" variety that I have recommended ...
On this past Saturday I began a long-term reliability test of four Nidec Beta V TA600DC thermostatically-controlled [internal control, two speeds, 235 cfm rating at 'high' speed] fans to replace one of the radiator fans on my wife's '94 Nissan that had not been funtional for at least a year or so ... this will be a bit more rigorous test than front fender oil coolers on a 911, since the radiator runs more or less around 195°F anytime ambient temps are above 35°F or so ...
http://www.nidec.com/ta600dc38/ta600dc38.htm
The temps underhood are at least 20°C higher than the rated specs, so I think this will shorten the fan bearing life a bit ... but at least I got the whole set for $20 on eBay, instead of the distributor price of $72 per fan!
I will let you know when any problems occur in 'testing!'