J Thomas
Newbie
I have a 1992 K1500 and I'm not sure what fluid to change out with. I got a fluid spreadsheet from O'Riley's and it notes 80W90 for both differentials. In the note section, it lists the following numbers: 12345836 for the front and 12378261 for the rear. I can't find either. Can I use AC Delco 80W90 and be fine? Also, does anyone know the fluid capacity for the front? Thanks!