That's great, 1) I didn't know you could put a CPU cooler on a GPU! 2) How are the VRM temps on that?
I have to give all credit to this man:
http://www.overclock.net/t/1237219/tript-cc-620-920-h50-h70-gpu-brackets-fan-grills-custom-case-badgesOtherwise I'd be using zip ties and probably making a mess of things.
The VRMs are still fairly warm. The Twin Frozr III's have a metal plate that covers most of them with a thermal pad underneath. They weren't cool to begin with, usually 80°C or more at times. But right now they're reporting 51°C/77°C with a 120mm blowing at the side. My reference 7970 has cooler VRMs -- 51°C/68°C.
The biggest pain is the copper shim you have to put between the block and GPU. I went cheap and got a 5-pack of 20x20x0.5mm shims for $2 on eBay.
FrozenCPU sells something similar for $3.99+shipping.