3rd member identification

Hey guys, second hit at this as I've found some more markings. I need to identify the 3rd member so I can get a new gear set(3.23 or 3.55 )
I know it's a 8 3/4 rear end but the 3 common castings don't seem to match what I have, I don't have the usual 41 or 42 , can't remember the 3rd one.
Please look at the photos ( yes oily and the wet is cleaning fluid ) does anyone know what the 3rd member is from the photos, cast numbers and the large 3 digits painted on, also the bottom is yellow ?...

3rd member identification
Author: ofb383