Yeah, full cover blocks are very thin, and they each have 2 inlets and 2 outlets which helps accommodate spacing issues depending on whether you go with barbs or compression fittings. With dual cards, you could go with parallel cooling in your loop. It would look like this (referring to the cards only, not the reservoir and other stuff):
You need a good pump to maintain flow in the rest of the loop, as the water will take the path of least resistance first. Still debate over series vs. parallel. But the second card in a series will tend to run hotter by about 3 degrees, sometimes higher depending on the rest of your setup.
This post was edited on 2/10 at 2:04 pm