Well, those thoughts aren't very in-depth, it's just a matter of simple observation... When you get your radiator in, strap a 80mm fan to it in a "blowing" position and feel the air coming out the other side. You aren't going to feel much, if anything at all. These little 12vdc 0.3A fans just don't have enough power to create any real amount of air pressure, which is what's needed to "blow" air through a radiator.
Now position the fan in a "sucking" position, and feel the air coming out of the fan (as well as feel the air moving into the rad from the backside). I can guarantee you that it will be at least double, if not more, than what you had in the "blow" position. These fans have plenty of pull to them, they're designed for it.
Want more reasoning? Open the hood on your car while it's off. Radiators are always placed in the very front of the engine compartment, and the fan is ALWAYS behind it. Notice something else? The fan always "sucks" the air through the radiator, and it almost always uses a shrowd
This is actually called a draw-through fan in automotive terms, and it's the most functional of all fan methods in automotive radiators. That's even considering that the air hitting the radiator may be moving at 60+mph if you're hauling down the highway.
The absolute best way is to have fans on either side of the rad -- one pushing, and one pulling. If you can't do that, then just have it pulling. If neither is feasable, you can try for pushing but your results will be craptacular.
ALSO, in a pull configuration, you want to do as much as you can to have the fan sucking air only through the rad and not from any surrounding gaps. A well-designed shrowd to seal the fans to the rad can lower your temps several degrees just by itself. If you don't have the room for a shrowd, try using some cork-tape or foam tape to seal the fan(s) to the rad. Generally, what you're trying to eliminate is any air that just kinda putzes in from little gaps between the fan body and the rad body.
Now, as for the reason why you want air to be sucked INTO the case rather than air being sucked OUT of the case is pretty simple too. The air outside your case will always be cooler than the air inside. You have a ton of electrical components in the case warming up the air. The air may only be several degrees (celcius) different between the two, but those several degrees add up quickly in watercooling. By sucking air out of the case, you're passing warmer air through the radiator. By sucking air INTO the case, you're passing cooler air through the radiator.
So the next thought is: All my radiator heat is going to make my computer cook! No, it really isn't. Want another example? Hop into your car, haul booty for a few minutes with the AC on high and get it nice and warmed up. Now pull into a parking lot, set the emergency brake, pop the hood, and leave the car running (and hopefully the radiator fan running) as you open the hood.
Most stock vehicles have a water thermostat around 185 degrees; that's more than hot enough to torch your skin if you touched it. Very carefully, feel the air that's coming out of the radiator fan and into the engine bay. Very obviously, this air is not 185 degrees.
The deal is this: sucking air through the rad and into your machine will result in the incoming air being a few degrees warmer, yes. But the net effect on cooling your components will be HIGHER than the effect of the slightly warmer air circulating in your case. Add a single 120mm exhaust fan in your case, and you've got an easy way for that 'warmer' air to get out.
Hope all that made sense
). I cant place them in the front because of HD cage placement and I cant remove it 
