Air flow meter swap for N/A
 

What exactly needs to be done to successfully swap the afm from the SC400 to a MKIII N/A? 550 injectors as well..?

This mod doen't work on the N/A. The 7M-GE uses a completely different type of ECU. You'd need to install a MAFT Pro in order to do this, but in that case you might as well go with a GM MAF (This can also be done with a MAFT Gen II.) or a speed/density (MAP) setup.