Depending on the motherboard you can fit up too a 60mm rad on top, I have only seen one that fit without an offset and that was by Tiny Tom Logan. I have a 45mm with a Z97 and it looks to have about 10mm clearance. The best fit if your looking to get the max thickness is 56mm. I know at least one manufacturer makes a 360mm x 56mm.I don't think 3 x 120mm in the front is possible.
7/19/15 at 2:25pm