How long will my CPU last at these settings?

I have my i7 920 @ 3.5GHz everything set to auto including voltage. I am on stock cooling and when running wPrime 1024M temps are in the low 80*C range, sometimes going as high as 84*C. Are these temps dangerous for my CPU to be running at? I'm planning on keeping this chip for no more than 3 years so I don;t care what happens after that I just want it to last me until 2011/2012.

What should I do, keep it at 3.5GHz with these high temps or go down to 3.0 which might last me longer? Don't tell me to go to aftermarket cooling because last time I tried that the metal backplate of my CM V8 shorted out my motherboard.

I just ran 3DMark06 and got max core temps of 74,74,73 and 71. Are these temps ok to run if the most cpu intensive programs I am going to be running are games?

The Tjunction Max specification of 100c is for throttle and shutdown overtemp protection ONLY. The limiting thermal specification, which is the value shown in Intel's Processor Spec Finder, is Tcase Max (CPU temperature), NOT Tjunction Max (Core temperature), which is a common misconception among many users.

Core i7 specs:

Vcore Max 1.375
Tcase Max (CPU trmp) 68c
Tjunction (Core temp) 73c

For more details, click on the link in my signature.

Comp