The North ME supports 120 mm radiators in the rear, up to 240 mm radiators in the top, and up to 360 mm radiators in the front. Note that different combinations could be limited. See below for more information.
Important: When front mounting a radiator, the maximum GPU length is 355mm minus the radiator thickness. If using a 30 mm thick radiator, the maximum GPU length is (355 - 30) 325 mm.
With a top mounted radiator, the maximum RAM height is 35 mm.
For front radiators, the maximum radiator width for 120 mm based radiators (120*/240/360) is 125 mm, with a max thickness of 55 mm, while 140 mm based radiators (140*/280) has a maximum width of 151 mm and a max thickness of 35 mm.
*Note that radiators of the size 120 and 140 mm only has the max thickness limitation if installed towards the bottom where the PSU shroud is located.
Note that 2.5"/3.5" drive mounts installed in the bottom can affect 360 radiator installations. Please refer to this link for additional information.