What are you using to check the temps? I hope you know the very second you stop bench marking the thing drops 10C instantly, so if you're closing the program and quickly trying to look at it, it's not going to show you the true load temp.
You need to have Rivatuners hardware monitor open while you run the benchtest and it keeps a bar line graph of temps over the course of time so you can go back and see what it was hitting.
These are the scores I got before and after overclocking:
Stock 6800GT @ DDR400 @ 2.6GHz - 71.84 drivers - 10,880 - 3dmark03(Build 360)
401/1101 6800GT @ DDR400 @ 2.6GHz - 71.84 drivers - 12,025 - 3dmark03(Build 360)
My CPU at 2.5GHz and 400FSB and 1gb of RAM is helping out there though.
Figured you couldn't go wrong with that leadtek, they seem to have awesome coolers, so keep pushing it