I was curious about gears versus chains, because "New Process" make both types with otherwise very similar internal guts.
From what I have read, gears are preferable for high speed very high mileage road use, but chains are considered more desirable for serious off road work.
It is not the chain that is itself stronger than gears, but the stresses put into the transfer case outer casing are very different.
Gears try to force themselves apart under extreme shock loads and may try to burst a light weight outer gear casing.
A chain under tension pulls things together, and may survive shock loads that may crack a light alloy gear casing wide open.
Chains do have the disadvantage of stretch, and there is usually no means of re tensioning.
The chain must be replaced when it goes slack.
Like overhead cam timing belts, transfer case chains have a recommended life and should be changed on schedule.
It is also interesting that some chain drive transfer cases designed for sustained highway speeds have provision for external oil cooling, where the gear drive transfer cases just run fully closed lubrication.
Anyhow, here's mine.
A New Process 124, fully open epicyclic centre diff, gear drive, with no low range.
Total weight 21 Kg (46 Lbs)
They put these behind 400Hp LS3 engines with 4L65 auto, they are plenty strong inside.