My AC equipped 63 had the fan clutch fail last month and after a lot of Web searching, I could not find a new replacement fan clutch for a 63 215V8 anywhere. I then found and downloaded the Hayden specification chart for their fan clutches. Hayden makes 220 different fan clutches, and by going to the process of elimination for each of the 220 numbers, I came up with one number that will work. Hayden part #2615 is a very close match and at $36.99 at the local O’Reillys parts store, it was worth trying. The 2615 is about a 1/2 inches thicker thus bringing it closer to the radiator, but there is still barely enough room to squeeze the fan belt past it and the radiator. Also, there are 6 very thin fins (as the picture shows) that face forward on the clutch, I removed those. As far as I can tell, they don’t serve any purpose and removing them is needed for radiator clearance. It’s a tight fit and had I removed the radiator it would have been a piece of cake, but it is possible to install the new clutch leaving the radiator in place. So far, it’s working perfectly, hopefully this tip will save somebody a lot of time if their clutch fails…..