I am getting ready to change out all of the fluids in my 77 B210. This is to include; engine - trans - radiator - brakes - clutch - diff - wheel bearings - and any other possible fluid's that I can get all over me. I am replacing all greasable parts (ball joint's, etc...).

Questions are, Walmart has a full synthetic for $17.99, is it worth the savings
are do I use the tried and true Mobil 1? I live in an avg. temp of about 60 Deg. It rarely goes above 80 or below 40. What viscosity should I use. What brand and weight of gear oil's should I use? Should I use a synthetic? Purple Oil? For the wheel bearings, is the Moly blend I read about in a "different a14 rebuild" recommended? What do you all use in the rad. (i have an overflow setup)
Dot 3 or 4 for brake and clutch?

I am not only triing to make this car last as long as possible, I am working at getting the best mpg I can muster (without any weight reduction).