So I have just bought my first monte carlo ss its a 1986 seems to be all stock other then the previous owner installed headers and took out the air injection. Was doing a little research and checking my rpo codes. Most of the codes made sense but I have three that I don't understand.
E5Z SPEEDOMETER ADAPTER (DELETE)
E7Z VEHICLE SPEED SENSOR (DELETE)
E9Z SPEEDOMETER KEY (DELETE)

Can anyone shed any light on why the car would be ordered with these options deleted?? Also how would the cruise function without the vss??