Steve : The ring gear has 74 teeth and the sun gear, on the input shaft, has 34 teeth. 74/34 = 2.176 ratio
The ratio of 2.176 stays the same with a 6 planetary although the planet set is much stronger and has a steel housing that holds the planets.
The 4-pin planetary which the redrives was manufactured earlier days has an aluminium body.
This is the set/up where the planetary is held stationary and the ring gear is the output
There is now a new version 6 planetary that fits in the 12 lug slots which has a steel casing