Understand. The description in the LH column is different than what is presented in TunerPro for the four letter code in the 16197427 ECU. It is really difficult to get the confidence that performing the change in the binary will yield the appropriate binary for the MPFI (batch fire mode) in the 489 Big Block.
I get that. GM never released the 7427 with PFI. Even the Edelbrock calibrations I've seen are not configured exactly the same as GM typically did with PFI swaps. What we talk about here is a combination of information from several sources that attempts to make the swap in the way we think GM would do it. This is not a road frequently travelled and over the years the path has varied as well as the results. Unlike Avionics, there is no program here to ensure you are not taking a risk before you are allowed out into the world. It's ok, though. If something goes wrong with the car you can pull it over and figure out what happened. ;)

There must be significant variable(s) for selecting going from TBI to MPFI. Have not yet seen these significant variables.
I'm not sure what you're looking for. There is no single value that makes the switch work. A successful conversion involves changing multiple values that work together to provide correct fuel in all driving conditions. The information Dave provided gives you the best starting point you will get.

There is one variable that describes CID for one cylinder. When multiplying by 8 cylinders, the total displacement does not work out.
Huh??? Stock BBC cal value is 56.66. 56.66 * 8 is 453.28. Actual displacement is 453.96. How much closer does the value need to be? Maybe you are expecting a level of precision from the tune and the ecm that really aren't there??

As far as changes related to injector strategy you will find that individual cell-by-cell tuning may be required after switching to "PFI Mode." Although the ecm calculates the correct amount of fuel to deliver based on calculated airflow and the number of injection pulses per revolution, it is not able to account for changes that occur because the manifold is not fuel soaked, because fuel is delivered at the valve, because response time during acceleration and deceleration change with the location of the injectors. When moving from four or two pulses to one, you might find that incorrect voltage compensation values meant to adjust desired "on" time affect driveablility in a dramatic way. This is another value the ecm cannot fix on its own. Additionally, you may need to do a "sanity check" on the values Dave W has posted to ensure they will work for your engine configuration. Watching the scan tool, looking at IPW and other related values is critical to help diagnose what happened.

FWIW, one of the best and most talented "ecm hacker" type guys I knew was in Avionics. Although he spent many, many hours teaching himself code he also had an advantage over all of us trying to decipher GM code back then. Because he had access to Motorola documentation, he found that many of the tech sheets for Motorola chips and circuits designed for automotive use came with example computer code. Quite often that code and the circuit matched GM equipment very closely. Where many of us had to work with dealership repair technician service literature and do our best to RE the circuits and the code, this individual had access to insider notes from the guys who designed and often built the parts GM was using. Maybe none of that information is available today but if I had access to that library I'd be searching for anything related to GM ecm's.