Hello,
I got a "new" used RADEON HD 5870 card. It has an arctic twin turbo II installed. Don't know if it is because of the cooler being too heavy - the PCB is bended a bit. I assume that it sagged during the years of usage with the ac cooler.
I was thinking about an aftermarket backplate - but at the moment I doubt that there are any for such an old model. If anyone knows about GPU backplates for this card, please tell me.