Light Weight Question

Hi Guys,
Only having my Landrover 1 week I am unsure what oils to use,
I am OK with the filler/level plugs but do not know what grade oils to use in the................

Engine,
Gear Box,
Transfer Box,
Diffs,
Front Hubs,
My Landy is a 1974 series 3 Light Weight FFR
Any help would be appriciated

Engine 20/50,
all the rest EP90

Cheers Davec
EP90 In the gearbox