C3AZ-4635-E (replaced C3AZ-4635-C, B7AZ-4635-A, B7A-7039-A, 21C-7039) .. U-Joint / Front/Rear applications: 1948/52 F1, 1953/56 F100, and...

This is the same 'Spicer type' as the front u-joint used on: 1965/73 289/302 Mustang / 1970/77 Maverick/Comet and a gazillion other 1942/80's FoMoCo vehicles.

So, there's no need to buy u-joints in Lockport NY (Mac's) and pay shipping charges, when you can buy them at local autoparts stores. Just take the original along to match it up.

Note: Ford changed the u-joints basic part number from 7039 to 4635 sometime after 1956.