What are your ambients like? My 2600K chips don't usually break 80C @ 5.0ghz and 1.48v with H70 cooling units.
Again, glad to hear that this is normal at least, but for a vcore of 1.3/1.29 on a 2600k with an H70, I was expecting slightly lower temps. I was looking around, and like turrican9 said, it's only when the vcore gets raised to about v1.35 that the temps start to get close to/break 70c. At least that's what I've seen, which makes me think that something could be wrong? I mean I'm getting higher temps at v1.3/1.29 than most people do with v1.35+ with higher clocks with an H70 or similar cooling solution.
Airflow is pretty good in the case (using a HAF X with most of the wires routed to the back of the case) and ambient temps aren't too high. Could one chip really run this much hotter than other chips of the same type? I even tried running the Prime95 blend test after about 8 hours with the Small FFTs test, and my temps were almost exactly the same (1-2c cooler in comparison).