i bought a scythe ninja 4 and its really good so far but i have a second 120mm fan sitting so i would like to put it on the heatsink,the problem is that it doesnt fit in the back so i cant go push/pull,is it better to put it in the top or the bottom or should i put on fan on top and on the bottom for push/pull?(my case has 2 exhaust fans one back one top and two front intake fans)