I thought I had my cooling issue solved with my new PRC cross-flow and dual 13" fans, but I was having a problem with the right side electric fan expanding when it warms up and pushing against the front of the AC compressor clutch. I figured I would be okay as long as I didn't turn on the AC, but it was also pushing the fan shaft into my radiator. I now have a fan-motor shaft sized hole in my new radiator. How much clearance do you need from the rear of an electric fan? I'm thinking 1/16" is maybe not enough.