1991 swap

Are the ECM connectors on the harness that is in there, that is currently connected to the engine?
Does this engine have an EGR valve at the rear of the intake on right side?
Can you post a picture of the ECM you have showing the connectors?
OBD1 will have a single large connector. OBD2 will have three smaller connectors.
1992-95 is what it is.20191202_121121.jpg