The W engines were never really intended for passenger cars. Chevy had the 348 in the final stages of development as a medium-duty truck engine when the supercharged 57 Ford 312's started eating the 283-engined 57 Bel Air's lunch at the drag strip. Chevy hustled up and cast a 3-2 carb manifold and had Zora Arkus-Duntov grind a hot cam, and rushed it into production in the first-year Impala in 58. Later, it was made into a 409, and even a few W-style 427's were built for NASCAR racing when FIA set the max displacement for race engines at 7 liters.
Jerry
