ROGER that!
I don't think the motors are all that different but the designations are a little hard to dechipher. I keep hanging on to higher kV motors too, and IC sized props (i.e., the Banshee would normally fly on a Fox 35 with a 10x6)
The only thing to keep in mind is what prop you want to use and an approximate rpm that you want to run at. I always use, for the first approximation, the rpm and prop I basically ran with a glow engine. That will set the kV and #cells needed in the battery pack.
Let the rpm target = 0.8*kV*battery voltage ( use ~10.5V for a 3s and 14V for a 4s) sets the rpm level.The 0,8 factor leaves you with surplus for the power in maneuvers.
so if the target is 9000 rpm, then for a 3s battery, you need a kV of at least ~1070 rpm/Volt. If you use a 4s pack, then you can get by with a kV of ~800.
Also note that the 4s battery and 3s battery will have the same overall weight --with the 4s cells being smaller in weight and capacity than the 3s cell (ratio=3/4) --but of course there are 4 of them rather than 3!
These days I am going to larger props than I used with glow, but since they turn slower, I can still use the same motor and battery as calculated above, and simply use the ESC throttle to set the rpm.