layout Platform G-body Engine(s) 231 CID Buick V6 200 CID Chevrolet 90-degree 229 CID Chevrolet 90-degree V6 267 CID Small-Block V8 305 CID Small-Block V8 Transmission(s) 4-speed (Saginaw)  manual 3-speed automatic 3-speed (Saginaw) manual 1978 All GM intermediate-sized cars including the Monte Carlo were downsized for the 1978 model year in response to the 1973 Arab