Hopefully this isn't a thread jack...
Reading thread indicates 3 parts needed to have pwm capable alternator:
1) ecm (+ programming)
2) harness (+ wiring connections)
3) alternator
got 1 and 2 semi-figured out, but which alternators are PWM capable? Have the same type alternator shown in pic 1 (a C5 alternator from GM FEAD) a corresponding 4 cavity matching plug and harness (I recall there are only 2 wires going into the plug), plus E38 ECM. Skimming rockauto looks like maybe the last time an alternator with the 4 cavity plug was used is in 2008 vans.