Overclocking of MSI R6870 Twin Frozr II with Radeon HD 6870 will reduces heat?

Hello friends, I am having MSI R6870 Twin Frozr II Radeon HD 6870 graphics card and was thinking to do overclocking, if I am going to that then it will be reducing heat or not? Earlier I have not done any overclocking and also I have heard the MSI afterburner is best tool for all this work. Someone has told me that I should try it doing it on R6870 Twin Frozr II card. If I will be doing on this then it will be changing only core clock, memory clock and also fan speed of it. Should I go ahead and do overclocking of the card from 920 MHz to 980 MHz and changing memory clock from 1050 to 1200 and make fan speed at constant one say somewhat at 80%. So when I will be doing all these changes then it will be making noise or not? I would like to play game such as Skyrim, would like to run it at 1920x1080, 8x AA, 4x AF, and other configuration at high settings. I have tried to find out that someone might have done it, so got one and founded that it he was getting 68C temperature and it was reported by MSI afterburner. When I have run game on my normal card then I get 80-90C temperature. But I was thinking that temperature will be going up, but it has gone down. Any suggestion or thought about it? Thank you.

It will be helpful for you and what have checked of the other person then he might be looking for load temperature of card. If you are doing then it will be set default fan profile to produce very less noise as it might be possible and would suggest that you better do not spin the fan up quickly enough. Whenever I do not do overclocking of my fan then set up custom fan profiles in afterburner and reason for that is graphics card will be remain nice and cool, which is one advantage to do it.