If it's below 75 degrees Celsius then I should be good
You should be good provided your VRMs arent burning... generally its a lot easier to keep the gpu cool than the vrms.
What about the placement of the Cooling fans? Any suggestions on that?
Not really. Not without knowing anything else, even if this is open air rig, closed case, what kind of case, ambient temps, whats in it or anything there isnt much to say. How about "cooling fans is good"