Ali,
The finned area of the one I got was perfect with one of the two concentric square gaskets removed from the CoolingWorks shroud. Split the two gaskets apart, keep the larger diameter one (the thin one) and use this one to fill the (very small) area between the outside of the core and the inside of the "lip" of the shroud.
The 7.25" size is height
including header tanks - remember that there are tanks on two ends so don't just carve a hole in your case somewhere until you're sure there's room for the header tanks.
If you've any question about the fit of this core with the CoolingWorks shroud, email be-cooling - they sell this shroud as well and should be able to tell you right away that they'll work fine together. Actually I'm surprised that the two product pages don't each mention the other.
If you are using only one fan, I'd suggest setting it up to pull air through the core rather than push.
Also, if you're cutting a square hole to mount the core, if you cut the hole a little smaller than the core size, you can use the "inner" square gasket (the one you didn't need when fitting the core to the shroud) as a gasket/cushion between your case and the core (not that you need a cushion or gasket, but hey, it's already die cut to exactly the right size...)
Enjoy!
Bob
PS Here's a
picture of my setup. I'm pulling with two stacked panaflos undervolted to 5V - it's pretty quiet. I'm also seeing idle temps in the ambient plus 8 or 9 range
but this is just what the CPU diode is reporting. It seems to go up and down exactly with the thermometer in my wall thermostat, so maybe it's a real temp (but maybe not, too).
Oh - and here's a
picture of the "notch" needed to fit around one of the barbs.