For 1980 the aged 250 cid (4.1 L) inline-six was replaced with a 229 cid (3.8 L) V6, 231 cid (3.8 L) in California. The 120 hp (4.4 L) V8 became an option on the base, RS and Berlinetta models this year. The Z28 hood included a rear-pointing raised scoop ( air induction) with a solenoid operated flap which opened at full throttle, allowing the engine to breathe cooler air. Speedometers now read 85 mph (137 km/h), down from 130. Z28s had new optional grey 5-spoke rims (later used on the 1986–1988 Monte Carlo SS) , a unique style upper and lower front grill and smaller revised graphics on its lower-door decals. The side scoops were also changed from a louvered design to a flatter one with a single opening. The 350 V8 was no longer available in the base, RS or Berlinetta models, being reserved only for the Z28 this year.
Source: Wikipedia, 2011