After looking around for the quietest 6xx card, I found out that the 660 version (non ti) was the quietest, so I bought this one.
Replaced the 560ti with an Nvidea Geforce GTX 660. I had to update to 10.8.3 first before installing the card. Replaced the card, then booted using the 10.8.3 backup Drive then did a fresh install of 10.8.3 on my SSD.
Installed OK, got stuck at spinning lines, thats normal I think cause multibeast is no installed Doesn't matter if I used the 550, 560 or 660, it always gets stuck there and no matter which system, from 10.7.1 to 10.8.3. Anyways I reseted and booted into backup drive, installed Multibeast to my SSD, then restarted, got stuck at grey screen because I forgot Graphic Enabler No, back to backup, used multibeast to set Graphic Enabler to No, then back to Booting of the SSD, now everything was perfect, also installec Cuda. Tried one game before bed time, Oblivion ran perfect on highest setting.
Now if only I could get wake to function properly (Black screen upon wake).
P.S. Card is nice and quiet compared to my loud 560ti.
660 stress temperature reached 79C
560ti reached 100C, which is the boiling point of water