'60 Chrysler 300F

Although the '60 300F and today's Sebring spiritually are galaxies apart, they do share a couple of common traits. The Sebring's face is a tastefully updated version of the 300F's impressive air-gobbling grille theme, and more significantly, both convertibles feature comfortable four-passenger accommodations, albeit arrived at from opposite directions. The 300F was reconfigured from a standard New Yorker six-passenger interior while the Sebring literally is a stretch from the contemporary norm-Cavalier, Sunfire, Camaro, Firebird, and Mustang convertibles-to allow rear passengers to climb aboard without contortions and to be seated without munching on their knees.

Another interesting similarity is that both the old and new Chrysler convertibles provide something special in their front seats. A truly exotic touch in 1960 was bucket seats-both front and rear-separated by a tall center console. To carry that idea to the logical extreme, the 300F's front buckets swivel outward a few degrees to aid entry and exit. The Sebring's contribution to advanced car design is a structural front seat sturdy enough to provide attachments for both lap and shoulder restraints. The beauty of this arrangement is two-fold: The belts fit better irrespective of occupant size because they track every seat adjustment. And they don't foul the pathway to the rear seat.

Convertible-top design is another of this body style's classic shortcomings that today's Chrysler engineers have strived to improve. The Sebring's rigid rear window with a built-in electric defroster is a major improvement over the 300F's flexible rear window, which is susceptible to damage and must be unzipped before the top is lowered. To hide the folded top, the Sebring has a self-supporting boot retained by a combination of hook-and-loop strips and tabs that tuck under the rear seatback and surrounding sheetmetal. The one down side is that this boot, when not in use, consumes most of the 11.3-cubic-foot trunk. Concealed snaps hold the 300F's wrinkle-prone boot in place.

Converting the Sebring to open air takes a mere 10 seconds to power the top down and another half minute to install the handy boot. Another improvement over the 300F's top design is the Sebring's full fabric headliner, which diminishes wind noise and conceals its aluminum roof trusses.

Chrysler switched from body-on-frame to unitized construction in 1960, which only added to the difficulties the company's engineers faced in creating a solid, rattle-free 300F convertible. Lacking today's computer-aided-design tools, those engineers simply added steel-beam reinforcements (principally in the door sills) until the shakes and quakes were quelled. That is, in part, how a four-passenger car became a 4800-pound behemoth. Sebring engineers, on the other hand, erred in the opposite direction. Their car is far lighter at 3432 pounds, as helped by the fiberglass hood and decklid.

Chrysler used the sledgehammer approach to give the letter cars exemplary performance for their day. In 1959, the first-generation Hemi V-8 passed the torch to a 413-cubic-inch "Golden Lion" wedge-head design. For 1960, a remarkable cross-ram intake manifold was added to position twin Carter AFB four-barrel carburetors 30 or so inches upstream of the combustion chambers they fed. The net effect was a loss of five horsepower from the previous year, but the torque peak was boosted by 10 percent and shifted from 3600 to a more useful 2800 rpm. Road testers of the day reported 0-60-mph times in the low-eight-second range, but MT (Feb. '60) clocked an engineering prototype at 7.1 seconds. Moreover, six privately owned cars were clocked at over 140 mph during Daytona's 1960 Flying Mile competition, and Andy Granatelli ran a modified 300F 184 mph across the Bonneville Salt Flats with help from a supercharger.