Front radiator: up to 360 mm
Top radiator: up to 360 mm
Rear radiator: up to 140 mm
Things to keep in mind
The Epoch XL supports graphics cards up to 425 mm. If installing a radiator in the front of the case, decrease the radiator thickness from 425 mm to get the new max length. A radiator with 30 mm thickness would allow a GPU up to (425 - 30) 395 mm.
If running a 360 mm radiator in the top and front at the same time, needing to put the front radiator as far down as possible, you need to move the HDD-trays from the bottom slot closest to the front to the second closest to the front, meaning that if you utilize both HDD-trays, the maximum PSU length would be 155 mm. This would not happen with only a 360 radiator, but a top and front mounted 360.