EvilDonnyboy,
actually it went up to 230 MHz RAM clock without problems when I once tried overclocking it and I didn't even go to the maximum (just stopped at 230), because it was only for fun and I didn't want to risk anything. (Why did you say 213 MHz by the way? Strange number...)
Btw, do you have a fan on the heatsink of your graphics chip? I think the non-max version has no active cooling by default ?! As you might know, the max has a fan and it runs pretty cool with this fan, so I may not even need that backside HS you mentioned (I doubt whether that helps much anyway...).
Such a 80mm solution is absolutely a non-solution for me...I tried it before with a Geforce and it was too loud for me. ("not all that loud"-arguments don't count anyway, because it has to be as silent as possible...).
Btw, I already had to bring the card in for the service. It was quite a mysterious thing but it works again. But, I can tell you, I was happy the card was still unmodded when the screen went orange...