Overclock 670 & SLI

[explodatron]

[Reposting since we're not allowed to bump and my last thread was closed]

So I have two 670s in SLI and have them overclocked using EVGA Precision X. I have the sync option on, but the clocks are different on each card. I have k-boost on so both cards are at their "boost" all of the time. GPU 1 is at 1162MHz and GPU 2 is at 1201 MHz.

When I run Heaven benchmark, GPU 1 sits at 1298 and GPU 2 sits at 1328. Neither card ever goes above 70C at any point.

Also is it normal that the max GPU clock offset I can get is +35? I've seen people say the can go above 50+. I don't overheat at 40 but I start getting driver crashes.

Is it just one card really doesn't like overclocking and the other likes it and that doesn't work well when using SLI?

Some pictures:
Heaven Benchmark
GPU 1
GPU 2

 

[unksol]

Why would you care about 15MHz in an off balance sli setup? 15MHz is nothing and cards vary

 

[explodatron]

Why would you care about 15MHz in an off balance sli setup? 15MHz is nothing and cards vary

Well it's not just that, but that I'm not able to raise my clocks near as high as most other people. That was the second part of my question. The small difference between the cards doesn't bother me much, was just wondering if it was normal.