Please forgive me if this has been discussed before. I have tried to search this but haven’t been able to come up with an answer. I have a 1966 L-72 Caprice. Recently I began having an overheating issue at idle. The radiator is the original 4 core. It has the correct 5 blade fan and fan clutch. After trying to get a fan clutch locally, I found almost all fan clutches the auto parts stores have for the 427 are 3.3” tall. The fan clutch In the car is about 2 3/4” tall. There are no markings on the fan clutch. The 66 assembly manual references part numbers 3814137,3814560, 3857530 or 3857531. The replacement part seems to be 3916141. My problem is the locally sourced fan clutches bring the fan too close to the water pump resulting in the fan not clearing the idler pulley. Does anyone know which thermal fan clutch would fit and clear the idler pulley? I’ve owned the car for 27 years and never had to replace the fan clutch. Any help would be greatly appreciated. Thank you.