Originally Posted by airdeano
its becasue of the elevation change in the grommeted holes. the fans lays flat on the
roof, but the mounting holes are countersunk (for the grommets) you need longer
fan screws to counter the countersunk holes..
The grommets are not countersunk on the 600T. They are just bigger holes and the rubber inserts stick out on both sides. After removing the rubber inserts, the whole grill is flat, while it's recessed as a whole (so the 25mm fans can fit under the top cover).
Another thing I did was to cut out the plastic cross-beams on the top cover, because otherwise they will interfere with the AP-15s. I also ended up cutting out the metal mesh from between the fans and the radiator, because it was causing a lot of noise (the fans' blades were spinning too close to it).