I purchased an aluminum three row radiator, shroud and fans for my 2005 Silverado Z71 on eBay from AlloyWorks. The radiator was very nice as well as the shroud but the fans were a bit weak compared to my stock setup, factory e-fans. I bought these to replace the Chinese made fans and planned on hooking them up to my onboard computer so they would work like factory. I cut the old fan harnesses and installed my own plugs and replaced the fans. These things are awesome. I believe that they are definitely underrated as far as cfm goes, not even close when compared to the eBay fans. They give the factory fans a run for their money and if I were a betting man would say they are better. They definitely sound better, they have more of a supercharger whine than factory wind noise. They are more quiet for sure. If I had any doubts during the purchase and installation, they were gone the moment the fans came on with my a/c, went to high with a/c on max and came on low when coolant temps hit 202*, all factory settings. I haven’t had the temp up to test them on high for that setting, I will have faith, so far so good. Would most definitely purchase again, especially at that price, $25 a piece below anywhere else.