Been a while since I have done any GPU testing too. I know skinnee did some installing of dallas probes on the card itself to get good VRM temps. Not sure what the titan has onboard. I would tend to probably stick to using the kit contents TIM and pads as that is probably how most will use them, but I'm not sure about mounting numbers etc. You might only get one shot at it depending on what comes with he block. Haven't a clue on the stress test these days.

Still have my 570gtx on air. Last GPU I had on water was an 8800 and my son stil has one running.

As far as pump/loop. A separate loop might help isolate heat and you could certainly dial down pump speeds and even install a valve if need to really dial down flow rates, but there is always a desire to see actual CPU + GPU loop testing too. Obviously you cant test Quad SLI parallel on all the blocks though so flow rate testing will have to do.

If you could test down to .3GPM that would be close. I would start with one and find a pump power that matches something close to .3gpm, .9gpm, 1.5gpm and let the restriction vary actual flow a little. Performance at like pumping power and restriction is what I like to see, then the blocks restriction is automatically factored in a bit.