Usually the Speedi-Sleeve you need is 99387 (from 3.873 to 3.879) and it looks like the image below. I've been told by some that the Speedi-Sleeve can be polished after installing, but I've not done that before and since it is only .012" thick, I wouldn't go too far...
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
