Not looking for what you would suggest. There are tons of threads on that. I couldn't find the specs by searching around. All I found was use this or that.

There is a time and place for everything and for one of my vehicles, I'd like to use the stock weight t-case fluid.

My GVR4 manual cites:

"Hypoid gear oil, SAE 75W/80W conforming to API classification GL-4 or higher"

Not sure why it would be any different for a 1g DSM.

Thanks for the info.

It likely says to use GL4 because GL5 wasn't available yet.

There are no brass parts inside a transfer case, so use whatever GL5 gear oil floats your boat. I use the heaviest synthetic I can get my hands on- 75W140 mixed 50/50 with Lucas Oil Stabilizer to prevent/combat unwanted seal leakage.

Thanks. I hear you on the seal leakage. This is for my 93 DSM, so I am trying to to find the lightest possible viscosity that the T-Case can survive while the car is basically stock. The 93 is my ongoing fuel economy project. It looks like 75W-80W is the stock spec. I'll use the MTL I have laying around then since it is actually 75W-80W.