I believe I have read somewhere in this forums that the leaked images of the HD5870 cooler shows that the mounting it's the same than HD4000 series, like they were the same than HD3000 series, like they were the same than X1000 series (the different one was HD2000 I think) so it seems that a GPU block / cooler (while it isn't full cover) for the previous gen should be compatible with this one...