1970 was a great year for muscle cars. It happened to be the last year for high compression V8 engines for all GM cars due to the upcoming 1972 unleaded fuel mandate. Even though 1970 was a pinnacle year for muscle car perform, the Buick GS equipped with the Stage 1 455 cubic inch V8 was at the top of the heap. 1970 was indeed the year when Buick showed the best muscle cars who was really boss.