Oil for transmission and transfer case

I'm a little surprised I could not find this answer in past posts so maybe I'm not searching right.

I'm in the process of swapping a SM 465 transmission and Dana 300 into my '73. I'll have lots of questions to come, but today I'm wondering what is the best type and weight of gear lube to put into my rebuilt trans and transfer case?
I also have a question about knowing how much oil to add to the D-300 with it clocked (I'm hoping to get it horizontal)?
Thanks for your time and opinions in advance.

 

I thought I'd post what I found so far (for the next guy who comes looking).
On Novak's site there is the following recommendation:

When filling your 465 with gear oil, we recommend that you select a conventional mineral oil or a para-synthetic in lieu of a full synthetic oil. Properly assembled manual gearboxes do not have the thermal strains seen by combustion engines or hypoid gears. Synthetic fluid in these gearboxes, while not harmful, is probably an economic waste.

Hypoid gear oil is sulphurized higher than transmission oil and can be mildly corrosive to the non-ferrous alloys used for synchros, bushings and thrust washers in these transmissions.

An 80W-90, API-GL5 or MT-1 rated fluid is very good. Some claim faster shifts from using a 50W engine oil in their transmission and we do not consider this to be contraindicated.

Now I just need to know how much oil to add to my Dana 300 now that it is clocked (I'm hoping to get it level) and how to check in the future to know if it needs oil.