Used ECM.  This is GM 1226025.  You will need to replace the PROM with your existing PROM for proper engine running.  This fits the following applications:

1983 2,8L V6 VIN 1, B, L, X, Z

1983 3.8L V6 VIN 8

1983 5.0L V8 VIN 7, H

1983 5.7L V8 VIN 6