Hey, my 6970 is oc'd to 975/333 at stock voltage. I get about 410 mh/s and it runs about 78ish degrees max. Is your card an XFX as I've heard of issues with not getting as high as overclocks due to the poor fan. And I use -v -w128 -f0 on my 6970 on GUIMiner.

Edit: Mine is a Sapphire 6970.