If you can find a 4.10 gear from another HO52 the swap is easy. Pull the axles, disconnect the driveshaft and swap out the pumpkin. A better swap is to locate a 14 bolt corporate that is the same width between the drum faces, so your tires will fit in the fenders. Most of these had 4.10 gears, but there are many with 3.90 and 3.73 gears, which I would look for. Best to find a junkyard that specializes in Chevy trucks. They will be a big help, especially if you can talk with an old guy. You will need to weld on your spring perches. And if needed, the housing can be narrowed by cutting and welding.
