Yes exactly that, I don't use anything like kombuster as I think they unnaturaly stress a card. I've found if heaven can run fine then games run fine.
I played through all of Batman AC and Crysis 2 with these clocks.
Edit: The only reason I had it on stationary rather than the demo loop was so I could check that each time I increased core or mem the actual fps went up as I have read people ending up with less fps with higher clocks, especially mem
Final question for you i promise. How long did you leave it running till you upped the clocks again?