OCing 2 8800 gs's

so I currently have 2 8800gs's sli and I have them currently overclocked to match each other (XFX AND EVGA) I wanted to push them a little bit higher to match an 8800gt speed and I ran ATItools for 6 minutes and got no artifacts, but the temp of one card reach 69*c (evga) while the other held at 57.

So my question is what kind of temperatures can video cards handle and what are good temperatures under load? (Typically play TF2 and L4D).

Specs:
cpu: q9300 quad core 2.5 ghz
MoBo: Asus striker II formula
Mem: 8gb (4x2gb) g.skill pc2 8500 (running at 800 mhz 5-5-5-15).
gfx:2 8800GS's pcie (SLI)
sound: SB Xi-Fi Xtreme
PSU: 650 watts

thank you