yup... need to upgrade. They don't pull enough air to keep the truck cool in the summer heat. I read somewhere that the vette fans and NBS truck fans pull at least 6000cfm. Mine only pull 2000cfm. I'm fine with it on the highway, and in cool weather, but summer heat overheats motor within 2 minutes. God forbid a traffic light cycle last that long.

Pay attention to when the video first starts. You'll hear the fuel pump prime, and the fans whine. I may go back to a stock fan clutch & shroud. I'll see what the local salvage yards have in stock.