Dang, where are all the gear drive guys that can explain this. Hope they show up soon since I would also like a better understanding.
What I know is pretty similar to Marty. The IH Cub Cadets used the same rearend as the IH Farmall Cub and I assume the Cub Lo Boy tractor. If you pulled the rear cover plate everything you see would look basically the same. Now, as far as the transmission section on the front of the rearend, I believe but don't know for certain, that it was really the same except some of the gear ratios were different. Can't say these details for certain. One of the gear guys needs to chime in.
Dustin - so as far as I know the gear drive tranny/rearends were all the same in all the gear drive IH Cub Cadets from the Original up thru the 82 series with some exceptions:
The EXCEPTIONS include the Model 1100, and the Model 482 and I believe some of the Model 582's (I think it was the Model 582 Special). The Model 1100 was made during part of the Quiet Line era ('74-'80) but not considered a Quiet Line since it didn't have the side panels covering the engine. It used a Peerless belt driven transmission/rearend and a Briggs/Scrapiron engine. It was an IH attempt to provide a lower end competitive priced model and basically developed a poor reputation compared to the other IH models. I believe the 482 and 582 (Special?) were somewhat similar in that they were the lower numbered model units from the 82 series but I don't know what exactly they used for tranny/rearends.
What I'd like to know more about myself is how the Hydro drive rearends differ from the gear drive. About the only thing I know is when you pull the rear cover plate off an IH Hydro you can see a big ring gear that sure looks about the same (if not the same as) the gear drive tractors. The one difference I am aware of is that the IHCC gear drive rearends have a drain plug on the bottom but the Hydro drive rearends do not, and I always wondered why IH didn't put one on the Hydros.
From the outside, looking at it from the back of the tractor, you can't really see any difference between the gear drive and the hydros, except where the fill plug is located on the back cover plate. (The gasket for the plate is the same for gear and hydro drives).