I had 1 cm clearance from the back, and probably 2 from the front, which is enough to fit a 40k cooler. The 30k cooler is 2 cm thick, the 40k is 3.5 cms ( only 1.5cm differnece but 30% more cooling) But you have an arb bumper, so my measurements shouldnt be the same.
When you come to do the instal, I would recommend a slightly longer hose. The one that came with the cooler worked but it was very tight, 10 cms extra hose would make life much easier.
When you come to do the instal, I would recommend a slightly longer hose. The one that came with the cooler worked but it was very tight, 10 cms extra hose would make life much easier.