I'm trying to figure out what differential I have, because the person before me removed the number tag that is usually located on the cover.

I do have a picture of the inside of it.

Does anyone know what this type is? Open diff / limited slip etc ??
I'm also using 80-90w gear oil, what are your thoughts?

 

Nothing but spider gears inside that carrier, you have an open diff. 80-90w oil is good, no additives needed. I've been partial to using Lucas oil, everybody has their favorite though.

 

Thank you Camaro69! X1000