By low and three I guess you mean 4-speed? Is it in your 1948 2-ton? If so it should be an SM-420 GM/Muncie. Lots of parts still available. I don't know about a "kit" as such, but Novak Adapters has parts for them, as well as other vendors. Here's a
link Many posts on this forum about the SM-420. Do a search of this site for loads of info. Good luck
