So I have this water loop. It was originally designed to be able to handle my CPU (QX9650) and my graphics card (GTX260-192). Loop is a Zalman Reserator 1 Plus, MCR320 rad w/D12SL fans, D-Tek FuZion w/quad insert, MCP355 w/XSPC top, and Koolance inline flow meter. The coatings on the Reserator are all intact and I do use corrosion inhibitors, never seen a problem but I'd like to thank everyone for their concern in advance. 
Thing is, if you notice above, I never got around to putting a block on the graphics card. In the meantime, that GTX260-192 blew up not once, but twice thanks to random video fan stoppages. I eventually got a GTX260-216 55nm as a warranty replacement and that one's served me well. I eventually wound up with a second GTX260-216 to match and I run them in SLi. I do not like the temps. The top card idles at 55C in a 27C ambient room.
I would like to complete the loop, but the thing that always stopped me was that nobody made a full coverage block for the 55nm GTX260, and then I lost my job. I'm looking at "completing" the loop as originally intended since I'm due for a teardown anyway. In order to use the current setup and watercool both cards, the calculated heat load is around 500 watts worst case. With that rad and my current fans, Delta T is in the 15-20 deg C range. That seems ... high. Better fans will get me to the 10-15 deg C range, but doesn't solve the water block problem. The "easy" solution is get a new spanky video card with a known-compatible block, but beating the performance of a pair of 260s isn't terribly cheap and I'm short on cash.
OK, so yea, that was a slight wall of text. Apologies.
TL;DR - Would you guys consider a dT of 15 deg C acceptable for that hardware?
Is there a full coverage block that works on the 55nm GTX260-216 cards or am I SOL on that count entirely, thus making this whole mental exercise of mine entirely pointless? EK lists the GTX275 block as compatible, but I've seen other sources say nothing works with my cards.
Thing is, if you notice above, I never got around to putting a block on the graphics card. In the meantime, that GTX260-192 blew up not once, but twice thanks to random video fan stoppages. I eventually got a GTX260-216 55nm as a warranty replacement and that one's served me well. I eventually wound up with a second GTX260-216 to match and I run them in SLi. I do not like the temps. The top card idles at 55C in a 27C ambient room.
I would like to complete the loop, but the thing that always stopped me was that nobody made a full coverage block for the 55nm GTX260, and then I lost my job. I'm looking at "completing" the loop as originally intended since I'm due for a teardown anyway. In order to use the current setup and watercool both cards, the calculated heat load is around 500 watts worst case. With that rad and my current fans, Delta T is in the 15-20 deg C range. That seems ... high. Better fans will get me to the 10-15 deg C range, but doesn't solve the water block problem. The "easy" solution is get a new spanky video card with a known-compatible block, but beating the performance of a pair of 260s isn't terribly cheap and I'm short on cash.
OK, so yea, that was a slight wall of text. Apologies.
TL;DR - Would you guys consider a dT of 15 deg C acceptable for that hardware?
Is there a full coverage block that works on the 55nm GTX260-216 cards or am I SOL on that count entirely, thus making this whole mental exercise of mine entirely pointless? EK lists the GTX275 block as compatible, but I've seen other sources say nothing works with my cards.
