rear end lubrication

[bigred1]

want to change the rear end fluid for my 1963 gmc pickup, 305 4 speed, 3/4 ton. What type of lubricate should I use?

[FetchMeAPepsi]

Lots of guys use regular Wal-Mart gear oil. Jay Leno recommends to use RedLine oil in older vehicles. From my notes, here's the type for our trucks.

57904 Red Line 75W90 GL-5 Gear Oil Rear End 1.3 Quarts each Front and Rear (2.6 pints) (41.6 oz)

[Clarke]

I've been using 75W-140 syn for years in all my rear ends that I tow and/or off-road with. It's a amazing how warm those rear ends get, that's why I use the heavier weight, plus the extra load/pressure.