Out of 3 X58 Pro builds, 2 ran in the low 70's, 1 in the low 80's. All 3 were 'heatsink' reset with AS thermal compound & now run in the 60's. It probably wasn't really necessary for 2 of them, but redid them anyway.
Edit: If anyone chooses to redo the heatsinks, & needs hardware sizes to replace the stock plastic pins, I used #4-40, 1/2" in length nylon bolts, nuts, & washers. (3mmx1cm ? metric?)