is it safe to run ram higher than 1.65v?

I do not recommend it. Even 1.65 volts is pushing the limits, since the memory was intended to be used at 1.5 volts. The reason so much memory runs at 1.65 volts is because it is overclocked, and the power had to be increased to get it stable at those speeds.

The next step up in power would be a .07 volt increase, which would put you at 1.72 volts, and that's just too high to maintain in my opinion.