We used to interchange the entire 1700 series. If it came from a Ford or IH it could have different side gears, but you have already checked the side gears. What you are doing worked 50 years ago and should still work. My concern was that Journeyman was going to try to put a 1700 series in a late model housing. I'm not sure if that would work because I am not familiar with the later model 2 speeds.