Radiator Sprint Car Downflow 1.50 in Outlet 20.17 in x 20 in small neck (4) -10 female AN port bung Inlets. Teams like Tony Stewart Racing, Steve Kinser, and Kasey Kahne Racing along with many others all depend on this radiator for quality and performance. The all-aluminum radiattors are the lightest, most efficient sprint car radiattors on the market. The cores are furnace brazed (no epoxy), and utilize the latest in core technology. The stock radiator features a 36mm single row core, with (4) – 10 female AN port inlets and 1-1/2 in or 1-3/4 in outlets with CNC billet radiator neck.