This should be great, but

Hey guys I'm currently mining bitcoins very effectively(for what i have) and its making me wonder if i'm doing something wrong(or right?). I'm running an evga gtx 470 right now(don't worry i'll be getting a 7970 hopefully within a month). So with my 470 I'm getting avg. 135.8 mh/s which is ~5 higher than what i'd seen online before, I've upped the gpu clock speed to 830 mhz and (tried) to drop the memory as low as it would go. However the memory clock stayed at ~1400ish despite it being set lower. I rebooted my computer this morning and now I'm running it at stock voltage, gpu clock: 830, Shader at 1661, and the Memory is down to 135mh/s. And that concerns me because that is MUCH lower than it should be despite it being lowered the the min. However because it is so low, my 470 is 70C at fan speed 75%. I'm not sure how to feel about that, I'm very new to mining and I'm just worried that running it so oddly would dammage my card (which i'll need for a while). Can someone tell me if its ok to run my card this way?

Nah, you can do whatever you want as long as the temps are down. For a card like that i'd say anything under 85 is safe, but try to keep it below 80 and you're 100% good.