I had a though that I can't quite shake. Maybe someone on the forum can answer this one:

Seems the gearbox Suffixes tell you about the innards. I imagine no one is getting out detailed blueprints to identify the reverse mechanism from a Suffix A from the one in Suffix B. Or, no one is trying to mix and match plated gears from a Siffix D with non-plated Suffix A/B/C. So, the Suffix tells you what's inside....but the spacing of the bearing journals on the case is the same? So, to my thinking, if you wanted to put 100% Suffix D parts into a Suffix A case...it would work? Can anyone confirm this thought experiment?

I mean, it would screw over the next guy trying to identify the parts. But, if I'm buying 100% new parts in there...why not benefit from the latest design fixes over the years and get a stronger overall gearbox? Would that be unethical? I could put a metal tag on the gearbox with notes or something. As opposed to just putting in the inferior reverse gear just because it matches the "A" stamp on the outside of the case?

What do you folks think?