29 posts · Joined 2008. #1 · Apr 20, 2009. I just bought a summit direct fit aluminum radiator, part number SUM-380457 . The radiator shop just showed me that the standard 5/16 1/2 x 20 inverted flair tube fittings that screw into the new Summit radiator transmission cooler are too short. There is not enough thread material to allow the S09r.