I tried the loser timings on my Leadtek 8800gt, With stock timings I can get 982mhz stable but 970mhz gives me a better score on 3dmark 06 by 10 points. With the loser timings I can get 1100mhz Stable but 1050mhz gives me the same score as stock timings at 970mhz and 1100mhz gives me 5points less.

My cores also like that 756mhz gives lower score then 738mhz which seems to be the sweet spot. And the sweet spot on the shaders is 1782 but they are stable up to 1890 with lower score.

My card came stock with 1.15 on the VCore under load.

Leaving the stock timing seems to be best unless you just want to show off a higher clock speed.