So far, my triple efan setup is barely managing my temperature for my 5.9. If temperature is over 90 degrees, temp starts to climb and hold just at 210. With DFW hovering over 100 Degrees the next few days, the temp is holding close to 215-220 degrees with A/C running. If I turn off the A/C, temp drops to 180. Without the assistance of the dual 10 inch efans mounted in front. The temp will climb to as high as 230 degrees fairly fast when using the OEM fan alone. I am confident the OEM fan works as well as the mark fan if it can be mounted further away from the radiator and have a custom shroud made for it. The OEM fan I have blows air really hard. I have to apply some muscle to hold my hand steady near the OEM fan as the fan pushes alot of air.

The dual 10 inch efans mounted on front, the blades are really designed to pull vs push. So being in push mode, I think I lost some CFM's with the blades running in reverse. I will start to browse around ebay and even flexalite websites to if there is a custom 10 inch pancake fan designed to be a pusher to push more air.

If temperature is below 80 degrees, the OEM fan alone will hold the temp at 180 degrees regardless of A/C on or off.