The engine was de-tuned to provide better fuel economy. The rear axle ratio was also made taller (from a 3.07 to a 2.65) to help with fuel economy. (both to the harm of performance) Also in 1980, the A/C was used to cool the fuel being fed to the engine to combat vapor lock.
Your best bet to regain that lost performance is to buy a pre-1980 car, or get a bigger engined car.
Hope this helps...Lee