You are correct the, the BCC is only referencing the calibration on the EPROM. The PCM itself is the same as long as it's the same service number.

In your case, since all you want is the connectors from the PCM to make an adapter harness, any of the PCMs with the red and blue connectors will work, there are several.

When I'm going to a possible unknown controller/ECM/PCM, I like to make adapters so that going back to the original ECM/PCM is simple and quick. After the tune is proofed out, I like to swap the pins, if possible.

In this case, since the '7427 will need to be retained to control the trans, making an adapter is the best option. It allows both controllers to control their respective parts. So in reality this is more of a T harness than a straight up adapter.