Differential end on top has "EDB - 38140" some symbol, then a 1. The bottom half of that side is "332." The backside of the differential only has "140."

I only have the pinion in hand, with the following numbers on it:
The main shaft has a 4 on it. The end of the gear has "8:39 GM," then "66 3862516."

Appreciate the decode.

Probably a 4.88 ring and pinion, as 39/8 = 4.875

How about the diff itself? It has this pinion with a spacer used for the ring gear, was hoping to use a 3.31 or 3.55 gear with this setup.

-shoe

EDB 30140 is a 3 Series posi.

If that is a 0, and not an 8, you can, Like Dyno said a 30140 is a 3 series carrier.
This past Friday, I just took out a 4.56 w/ spacer and replaced with a 3.42. Good gear and am well pleased.

Ok, the 8 might not be an 8, but it sure is hard to tell. I underlined it when I copied it down since it looks like there is a slight casting flaw on that number. Almost looked like one of my zero's in school where the teacher insisted that we slash them but I didn't like it and left it short.

If not an 8, a zero might not be my next bet. Sure seems like a line through the middle of it. Would a 3 or 6 even work though?

-shoe