Since nobody with more knowledge has jumped in I'll share my two cents. I do not have first hand experience with universal gpu water cooling blocks but I have done extensive research lately as I am going to be going that route myself.
I cannot say if that particular block will work or not, you will have the look up the compatibility on the manufacturers website. It most likely will since it shares the same mounting configuration as other blocks that are shown to fit that card. I would suggest taking a look at the ek bridge edition universal gpu block
. It has a bit more clearance between the pcb/vram chips and the block extension making it easier to attach ram sinks to the ram chips in that location. That is the block I've decided use on my 660 TI. You would also be able to take advantage of the ek dual parallel sli bridge
. Either block has good flow rate / low flow restriction and would be easy to add to an existing loop with most any pump.
One caveat to the universal blocks is that you must provide some form of cooling to the vrms and ram chips. This is most commonly done passively, provided your case has good airflow, using individual ram sinks stuck to each chip using thermal tape. It appears that at least part of that card's chips are covered by a heat spreader still once the gpu cooler is removed. This should make it even easier to provide cooling to them. You could also mount a quiet fan that blows directly over the ram sinks to provide even better cooling of those components without sacrificing much additional noise. This would be a good use for the case door fan mounts on some cases.
A big bonus of the universal water blocks, besides being cheaper, is that you can use it again on a new card unlike the custom tailored full cover blocks. The resale value of the full cover blocks also tanks once the card isn't popular anymore.
Edit: Here is a build thread of a member who went the route you are considering on his sli gtx cards to give you a visual idea: two4teezee's mATX SLIEdited by rebelextrm02 - 9/6/13 at 9:33am