RX 480 Normal OC? + Cooling

[Izumi Reina]

So just got my RX 480, and I just quickly overclocked it out of the box to see what I can get before heading to bed and I got 1350Mhz (1400Mhz wasnt stable), I havent tried within but is this normal (I come from the GTX 750Ti where +200Mhz is normal).

 

Also a quick question I have a lets say a 200mm fan pushing into a GPU (that is perpindicular to the fan) and a exhaust fan behind the GPU that is parallel, a quick drawing ish.

EXHAUST or CPU FAN = [1]

GPU = [2]

200mm fan [3]

Please note that the arrow after the number represents the way the air is big pushed, if it has no number it is vertical.

 

[1,<]     [1,V]

-------------------Wall/Backplate [3,<]

[2]

*Not to scale

 

So ontop of the GPU there is a single 120mm fan blowing onto the GPU would it be better if I made it an exhaust to blow out the hot air and not fight the 200mm fan?