1968 Pontiac Bonneville Convertible
The Bonneville sat atop Pontiac’s full-size range in 1968, riding a 124-inch wheelbase (three more inches than the Catalina or Grand Prix) and stretching 223.5 inches overall. The front end was revised that year to horizontal twin lamps and an integrated front bumper, replacing the stacked arrangement from the year before.
1968 was the last year Pontiac offered the 8-lug aluminum wheel option on its full-size cars. Available since 1960, the system (designed by GM engineer Clayton Leach) used finned aluminum brake drums as structural wheel centers bonded to 14-inch steel rims at eight points, giving the drums direct airflow to control heat. Front disc brakes made it redundant after this model year.
Bonneville convertibles received leather and Morrokide upholstery, rear fender skirts, and elm burl vinyl dash trim as standard (extras on the Catalina below it).
A four-barrel 400 CI V8 at 340 hp paired with the Turbo-Hydra-Matic was the standard engine; the optional 428 CI raised output to 375 or 390 hp.
Of approximately 104,900 Bonnevilles built for 1968, just 7,358 were convertibles, combining both standard and Brougham trim production.
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