Isn't it only the low range that is different?
Oh dearie me .....
Every gear can be a reduction gear, an equal gear, or an increasing gear.
In a series Landy gearbox, 1st, 2nd, and 3rd and reverse are all reduction gears. 4th is direct drive, no gears, "one-to-one", so we call that an equal gear.
Next comes the transfer box.
Typically a Landy HIGH range is a REDUCTION gear 1.41 : 1
and the LOW range is an even more severe reduction 3.32 : 1
That means in HI range the gearbox output shaft turns 1.41 times to turn the prop shaft ONE turn, and 3.32 turns in LO range.
The axles are REDUCTION gears too, probably 4.7 to 1.
In low range first gear therefore, the reduction is about 45 to one, thus MULTIPLYING THE ENGINE TORQUE about 45 times, but slowing you down compared to the speed you would be doing in top gear high range.
If you have 120 pounds-feet torque at the engine flywheel, by the time it reaches the axles in first gear low range it is multiplied to a whopping FIVE THOUSAND pounds-feet, which is why half shafts get snapped.
Some Series Landies may use ratios slightly different from these figures, but not so much as matters.
CharlesY