360 bhp, 454.2 cu. in. OHV V-8 engine, four-speed manual transmission, coil spring independent front suspension, live rear axle with trailing arm coil spring suspension, and disc-front, drum-rear power hydraulic brakes. Wheelbase: 112.0 in.

Chevrolet’s second-generation “Mk IV” big block engine debuted in mid-1965. In sales terminology, it was called the “Turbo Jet,” and appeared in 396 cubic inch form in the Corvette and Chevelle. Over the years, the 396 ranged from 240 to 425 brake horsepower and was used in Camaro, Nova, Monte Carlo, and full-size Chevy models, as well as in trucks. In 1970, a bored-out version with 402 cubic inch displacement was created, but sold as a 396 in smaller series and the “Turbo Jet 400” in full-size models. Only pickup trucks, oddly, correctly called it a “402.”

The 427-cubic inch Mark IV was introduced in 1966, as a production engine for full-size Chevys and Corvettes. Its heyday lasted until 1972, during which time it was offered in 390 to 435 brake horsepower guise, but it lived on until 1995 as a truck engine. From 1988, it had throttle body fuel injection.

For 1970, the Mark IV was stroked to four inches, for 454 cubic inches. The Corvette and full-size Caprice each received versions, as well as the new G-body Monte Carlo. It was also used in El Camino pickups and the equivalent GMC model, the Sprint.

In mid-1970, RPO Z15, an SS454 package, was released for Chevelles. The engine was an LS5 version with 360 brake horsepower. Other SS equipment included bright engine accents, dual exhaust, a black grille, wheel cutout moldings, power front disc brakes, special rear suspension, a “power bulge” hood, 14x7 Sport wheels with F70-14 white letter tires, and a heavy duty battery. Transmission choices were limited to a four-speed manual or a Turbo Hydra-Matic.

The recipient of a frame-off restoration, this 1970 SS454 Convertible Coupe has a Muncie close-ratio, four-speed, manual transmission and 12-bolt Positraction rear axle with 4.10 to 1 gears. Accessories include power steering, power front disc brakes, power windows, air conditioning, windshield washers, and an AM/FM radio. Although the SS badging is fairly subtle, the power bulge cowl induction hood, secured by hood pins, is a dead giveaway that this is a serious motor car.

It is painted Tuxedo Black with white SS stripes. The contours, paint, and chrome are all in excellent condition. The interior is done in black vinyl with a padded dashboard, all like new, and the instrument panel has a Clock Works retrofit quartz clock. The black vinyl convertible top has a matching vinyl boot cover. The engine compartment is clean and correctly detailed and underneath is gloss black paint; the exacting detail is evidence of a body-off restoration. The Sport wheels are mounted with Firestone wide oval tires, and an owner’s manual comes with the car.

Just 7,511 Chevelle convertibles were built in 1970, including both Malibu and SS versions. The number of SS454 cars is necessarily much smaller. A superb example of the first-year Chevelle 454, this car is rare and extremely desirable. It is bound to please a new owner.