Hello forum friends,
I have scanned the forum for the info I am seeking but ended up a bit confused, so I will just ask outright and hopefully get a definitive answer without major debate, and thank you all in advance for your responses and consideration.

I own a 138" wheelbase 1990 Ford F350 4X4 Cab/Chassis truck that I have installed a factory dually pickup be on.
It has 34,000 original kilometers, is in all original condition prior to my ownership and the box conversion and runs perfectly.
The powertrain is as follows: 460 cu.in. (7.5 liter) EFI, ZF S-42 5-speed, Borg Warner 1356 transfercase, Dana 60 Solid Front Differential, Sterling 10.25" Solid Rear Differential (both with 4.10:1 open gear).
I have decided to run Shell Rotella T6 Synthetic Motor Oil for the 460 engine.

My question is with my decision to narrow down my choices and to run AMSOIL (only) synthetic fluids in the remainder of the powertrain but I would like recommendations to the weights/viscosities for each please.

1. ZF-5 Transmission? i.e. Is "AMSOIL Signature Series Multi Vehicle Severe Duty Synthetic ATF" the preferred choice for the transmission
2. BW 1356 Transfercase? What AMSOIL ATF do I use or is it the same as in the ZF5?
3. Dana 60 Front Diff? Is AMSOIL Severe Gear Synthetic Extreme Pressure Gear Lubricant the choice and what weight (75W 90 or 75W140?)?
4. Sterling 10.25" Rear Diff? Is AMSOIL Severe Gear Synthetic Extreme Pressure Gear Lubricant the choice and what weight (75W 90 or 75W140?)?

Many thanks in advance for your assistance with the AMSOIL quesions - Pete

 

My son is am Amsoil dealer and that is what I use in my 1988 460 F250. Go to the Amsoil website and there is a window where you can enter your trucks info and your options will be presented to you.

 

Amsoil is good I use it in my 96 F-350 w/460 and Gear Vendor O/D