I don't have concrete evidence, but to my knowledge both '78 and '79 LRE's were available in California. As for how a smog pump works, I have a theory. They claim it allows for unburned gasoline in the exhaust to burn due to the introduction of more oxygen. My theory is that all it does is dilute the exhaust by introducing "clean" air to reduce the parts per million of the exhaust coming out the port.