Chevrolet launched the Series AD in 1930, replacing the previous AC models. The AD retained the new “stovebolt” 194 cubic inches (3.2 L) six-cylinder engine from the Series AC, but with bigger intake valves and smaller exhaust valves, along with a new manifold, raised power from 46 hp (34 kW) to 50 hp (37 kW).
The suspension now included hydraulic shock absorbers and the fuel gauge was moved from the tank to the dash panel, along with an angled, non-glare windshield and new instrument gauges with circular shapes and black faces, smaller 19″ wheels using wire spokes while hickory spoke wheels were now optional.
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