The Packard Balboa was a concept car from 1953. This hardtop concept was based on the Packard Caribbean convertible.
The main point of interest on the car was the canopy-style C-pillar. Caribbeans never received a hardtop like the Balboa's, but they got a conventional one (covered with Hypalon) in 1956.
The drivetrain of the Balboa was stock Caribbean with a 327 c.i. Straight Eight engine that was distinguished from lesser Clippers Deluxe's engine by hydraulic valve train adjustment and from the more expensive Patrician 327 by 5 instead of 9 main bearings.