I believe my card is slightly different, but it is a superclocked edition. It's not a core 216 (at least I don't think it is), but I've been able to hit 715 range on my core, but I can't seem to break 1040 on my memory clock for the life of me. All cards are gonna behave different I suppose. I've heard of some people getting pretty high memory clocks on my card.
If you are just adamant, I guess you could try some voltage increasing, but that sounds like more trouble than it's worth unless you just want to see how far you can push. Not to mention frying expensive video cards is lame