280 bhp, 348 cu. in. OHV V-8 engine, two-speed Powerglide automatic transmission, coil spring independent front suspension, live rear axle with coil-spring trailing arm suspension, and four-wheel power hydraulic drum brakes. Wheelbase: 117.5 in.

Chevrolet embarked on a major redesign for 1958. Starting with an all-new “Safety Girder” chassis, a cruciform-type backbone without side rails, the evolution included lower, wider, and longer bodies. The wheelbase grew two inches to 117-1/2, and styling adopted a sculptured theme, with cove-like rear fenders wrapping around into the rear fascia where the taillights were ensconced.

Emphasizing the newness of the bodies were new model names. The One-Fifty and Two-Ten series were replaced by Del Ray and Biscayne, respectively. Bel Air remained at the top of the catalogue, but a new subseries was created for the convertible coupe and hardtop sport coupe. Called “Impala,” after the swift African antelope, these two body styles had distinctive, rear sheet metal with three taillights per side and special trim with simulated side air scoops.

But that was not all. While the range of six-cylinder and small block V-8s was continued, a new powerplant, the first of the big block genre, was introduced. Originally conceived for commercial use, the Turbo-Thrust V-8 displaced 348 cubic inches and developed 250 brake horsepower in its basic, single four-barrel version. There were also two Super Turbo-Thrust options, both 348s with three 2-barrel carbs. The 9.5 to 1 compression version developed 280 brake horsepower, while the other, with 11 to 1 compression and a high-lift cam, made 315. Turboglide, a constant-torque, dual-pitch, automatic transmission introduced in 1957, was available as an alternative to the well-regarded two-speed Powerglide. However, the new unit proved less popular and was complicated and difficult to repair.

This Cay Coral Impala Convertible has the Super Turbo-Thrust, three 2-barrel, 280 brake horsepower, 348 engine coupled to a Powerglide automatic. It is well-optioned with power steering, power brakes, power windows, a power seat, and a Wonderbar signal-seeking AM radio with twin rear-mounted antennas. A chrome tissue dispenser is fitted below the dashboard. There are fender skirts and a Continental kit on the rear, in addition to a spare tire in the trunk.

The interior is done in a nicely harmonizing multi-tone motif, with coral vinyl surrounding black, white coral, and charcoal insets. The floor has coral carpet, protected by red Chevrolet rubber throw mats. The white vinyl convertible top is furnished with a coral vinyl boot cover.

All body contours and paint are excellent, as is the chrome brightwork. The doors shut properly, with correct alignment and even gaps. B.F. Goodrich 8.00-14 Silvertown whitewall tires are mounted on standard rims with spinner wheel covers.

Intro-year Impalas are very desirable, and the Super Turbo-Thrust 348 is particularly prized, especially when teamed with the reliable and trustworthy Powerglide. This car is an outstanding example of the breed.