Newly purchased 72 C20

[72restorationvirgin]

As you can see I'm new to the forumn. I've been looking on here for the past couple weeks and finally man'd up to join. I recently purchased this 72 C20 with a GM 350 crate motor/4 Speed on the floor. I'm going to change all the fluids and was wondering how many quarts does the Dana 60 rear end take? I'm looking at just putting Royal Purple in it but need to know how many quarts to buy at whatever depressing price it will be.....

It's obvious everyone likes pictures so I attached some. My basic plan is to slowly restore it. As you can see it's already been painted (previous owner(s). Needs painted again but it works for now. I had originally planned on bringing it back to the Medium Blue/White but the black is starting to grow on me...It's a pretty solid truck minus the usual spots like some minor rust in the rocker's, edge of the floor pans...