So, an AS3-71C is also known as a 10-17-000-009 and is 2.10:1 standard rotation.
It is normally paired with the same, if one engine is counter-rotating or an AS3-71CR/10-17-000-010 if the transmission is doing the counter rotating, the 71CR reverses the engine rotation.
If that model wasn't available that year in counter rotating, it might also be paired with an AS7-71CR/10-17-000-008, which is the same transmission, also reversing the engine rotation, but in a 1.91:1 ratio.
I'm guessing from what you've written and just guessing, that you've got two standard rotation engines with one 2.10:1 standard rotation transmission and one 1.91:1 reverse rotating transmission.
What are your engine serial numbers? We might can get another data point by decoding them. They often include a build number and a digit, an X, indicating reverse rotation, if they are reverse rotation.
Those transmission can work with normal or reverse rotating engines -- but the internal oil pump needs to be (re)installed indexed into the position corresponding to the engine rotation.
If you DM me with your email, I can send you the manuals for those transmissions and you can see the model chart and how the pump works.