I reccommend getting rid of the clutch fan and going with a manual fan. I had this problem with my bird last summer and it was a new rebuild. I tried 3 different clutch fans, and even the severe duty cluth fan, non of them cooled my bird as well as the manual one did. Clutch fans "do not" spin at RPM at all times, only when kicked on. Run a 195 thermostat, and the manual 7 blade fan from summit racing, that has been the best combo for me. Good Luck, and keep us posted n your progress.