[vin63]

Talking things over with the folks at Derale on my build (no belt-driven fan), they explained that a properly functioning shroud is essential with AC. It's also important to make sure that if in a pulling configuration, the fans are mounted so that the blades are operating inside the shroud. I run dual Derale HP 12" fans and mounted them so that they are halfway inside the shroud. My truck runs around 210-220 in traffic on 105 degree days with the AC running. Derale now makes integrated fan/shroud kits (I wish they had them back when I was building my C10) for standard-sized radiator cores, but they will also help with custom applications - Shrouded Power Packs: https://derale.com/product-footer/el...ual-powerpacks