Got a pic? Most likely, it will be the std Eaton suppkied diff used from '55-'62 (some '63s used it too). S far as parts go, all of the seals and the crush sleeve are still avalable, gears are iffy. I know that there is a 3.38 gear set, but it can be difficult to get depending on production. Spiders are not available, either. I do know of a company, Tom's differentials, that makes replacement axles that convert it to the a 30 spline, allowing the use of '65 and later 12 bolt spiders. Most likely, though, if you want to stay with the original gear ratio and axles, used is about the only way you're going to find them.
