GPU Block Questionable Pad Contact

I'm installing an EK waterblock on my Radeon 6990... (my first water cooling build)

http://www.ekwaterblocks.com/shop/ [...] ickel.html

So, the first problem was that after checking the contact pattern between the full cover block and the 2 processors, 8 memory IC's and the VRAM lines, almost nothing was making good contact. This was because the standoffs were not screwing into the plate deep enough. So I tightened them a LOT more, and now I am seeing good contact between the block and the processors (covered by thermal grease MX-2) and the IC's (covered by thermal pads sitting on top of thermal grease) but NOT all of the VRAM mosfet-tiny-things.

I'm just not seeing quite as solid of the greasy footprints that the pads leave on the waterblock.

So, my question is...

How important is it that I can see a clear, strong footprint for every single component?

If it's super important, then how do I make better contact? I can't tighten the standoffs more without a lot of effort, and the manual warns against "overtightening which may damage the nickel." The thermal pads came with the block and everything as did the standoffs, so they're the right thickness, and I definitely have them applied correctly based on the manual.

I'm not looking to damage my GPU, especially considering that I won't be able to check temperatures until I boot into windows, which takes a bit of time due to my RAID setup... also, I'm not sure I can check the temperatures of each individual component...

Thanks for you help.

(Edited URL)

If they are making moderately good contact, I would think this is a good sign the block fits appropriately. Also, given that the block appears to fit fairly well, I would assume it is a reference board? I don't know as much about AMD boards, so someone feel free to correct me here.

It is possible that your standoffs not threading completely might be the issue...do you have cross threaded screws or holes?

I agree on the threads...

@CKLayoka- can you pull the block and see if the threads completely thread in when the block is off the card?

Sorry for the delay. Just moved back to college.

So what I ended up doing was switching some of the standoffs around, which for some reason worked because some standoffs worked better than others. I eventually achieved excellent contact and had solid temps (<10 delta on full load with CPU and GPU loop). Unfortunately, I had to RMA the graphics card for artifacting that I had noticed BEFORE removing the stock cooler but for some reason completely forgot about. I'm just waiting for the refund to come through and then I'll buy a new one from a different manufacturer (XFX for warranty reasons).

As to the pads: .5 mm worked fine, I just needed to tighten things up a bit.
Tightening screws: thanks for the tip, medmn. I'll remember to start with the perimeter next time.
Reference cards: No, there are no 6990 non-reference cards anywhere.
Standoffs: No, the standoffs do not go through the holes in the PCB, but that was the way it was designed.

Thanks for your comments, everyone. I was pretty psyched when I first booted up and watched my temps. Can't wait to get a 6990 back in my loop.

I'll write up a full build log and take pictures for the forum when everything is finished in a week or two.