Overclocking my Gtx 570 SLI

Hello everyone.
I was thinking of Overclocking my GTX570 SLI, and was looking for suggestions considering this is my first time making something like this.

I recently ran the Uningine Benchmark and came out with the following results:

(Pc)
Intel I5-3570 3.40 Ghz
2x Gtx 570
8Gb Corsair Vengeance Ram
Corsair 850W PwrSupplier
P8Z77-V pro motherboard.

Uningine:
3d11
1920x1080 4xAA
Ultra
Tessellation = Normal

My first GTX570 states:
Graphics = 750 MHz
Memory = 1950 Mhz
Processor= 1500 mhz

And the second:

Graphics = 800 Mhz
Memory= 2000 Mhz
Processor = 1600 Mhz

The first card reached 93° , while the other one 97°.

My average fps was 60.4, with a score of 1521, with min 22,8 and max 119,1.

Now, do you think the results I get are okay for my pc build?
In case I wished to overclock my GPUs, what would you suggest?

I also thought, if I cap my FPS in some games at about 40fps, is it a nice idea? Just to avoid getting those awful frame skips from 60 to 40.

Thankyou in advance.