Intel recommend a maximum temp of 70c with prescotts, and my 3.4ghz ran at 60c idle with the stock pile of total crap HSf. there is no reason yours should be any higher. 80c is also very close to thermal throttle and shutdown. Semiconductors that run hot will have their lifespan reduced, and i think that is mentioned in mosst Intel documents.
Change the fan to a freezer 7, it's cheep, and has the same mounting as that pile of junk that Intel produce.