Chevrolet’s 1955 Bel Air debuted with an engine so influential that every Chevy small-block built for the next four decades traced back to it — even though the earliest examples burned oil and struggled on regular gas. From the 195-horsepower Super Power Pack to the rare fuel-injected 283 offered in 1957, the TriFive years defined an entire era of Chevrolet performance. Read on for the full year-by-year breakdown of what made these cars so significant.