"FCC/AIR DATA COMPUTER INTERFACE
Two air data computers provide air referenced data to the Autopilot
Flight Director System (AFDS). The left air data computer ( ADC)
supplies data to the left and center FCC and the right air data
computer supplies data to the right FCC. Each ADC transmits a source
destination identifier ( SDI) code to identify the source of the data."
Note however, there is signal sharing between the FCC's. With dual sensor data (such as ADC's), in the air, the FCC's are forced to use a particular ADC depending on A/P or F/D selection. In a lot of cases, the Left ADC will be providing data. The Right ADC will be used if the Right A/P is selected or if the F/O's FD (only) is on and no A/P is engaged.
I seem to recall that the source select switches may also influence what feeds what.
Note that there are variations from aircraft to aircraft. It's best to ask the fleet specialists.
Regards.
NSEU