Convertibles, like this GT-500, joined the Shelby-Mustang stable for 1968.

The 1968 Shelby Mustang

The 1968 Shelby Mustangs got a heavier facelift than the regular-production 1968 Ford Mustang. The hood sprouted louvers and a full-width scoop placed nearer the panel's leading edge to improve airflow to the carburetors. Below was a wider grille with square foglamps (not driving lamps) sitting outboard. Taillamps adopted the sequential-turn-signal feature from the 1967 and 1968 Mercury Cougar. Carroll had built a few '66 convertibles as gifts for friends, but now offered ragtops as regular models -- a GT-350 and GT-500 with a built-in roll-over hoop that enhanced safety but looked a bit awkward with the top down. Though some '68 advertising used the name Shelby Cobra instead of Shelby GT, the cars again displayed Shelby GT-350 or Shelby GT-500 labels.

To meet emissions limits, the GT-350 switched to the new 302 V-8. Despite a deep-breathing four-barrel Holley carb and hydraulic lifters, rated power was down to 250. To compensate, Shelby revived his Paxton supercharger option from '66. It added about 100 horses but again found few takers.

That's because Shelby buyers still much preferred big-block power. Early GT-500s retained the 428, albeit re-rated to 360 horsepower. However, some later cars got ordinary 390s when a plant strike created a spot shortage of 428s. Oddly for straight-talking Shel, customers weren't told of the substitution, though it was very hard to spot. And mid-model year brought redress in a replacement 1968 Shelby GT-500KR ("King of the Road," a title likely taken from a hit tune of the time). Also offered in fastback and convertible form, the KR packed the Cobra Jet engine, muscled up with big-port 427 heads and larger intake manifold and exhaust system. Horsepower was 335 advertised but was probably closer to 400 actual, as torque was a thumping 440 lb-ft at just 3400 rpm. Shelby also tossed in wider rear brakes and special exterior trim. Transmissions and rear-end ratios carried over from the GT-500, but the KR was quicker, generally matching the peformance of CJ-equipped non-Shelby Mustangs.

The 1968 Shelby GT-500s came with, at first, a 428 "Cobra" V-8 uprated by five horses to 360.

Though inflation was pushing up prices on most cars, the Shelbys didn't go up much for '68. The 1968 Shelby GT-350 fastback started at $4117, the 1968 Shelby GT-500 at $4317, the 1968 Shelby GT-500KR at $4473. Ragtops listed at $4238 to $4594. Partly as a result, Shelby volume rose for the fourth straight model year, hitting 4450 units. But it would go no higher. Increasingly potent regular Mustangs were fast eroding the performance aura of Carroll's pony cars. And Ford was now calling all the shots, fast morphing the Shelbys from no-nonsense racers into fast but cushy cruisers. In a telling development, Ford shifted '68 Shelby production from California to Livonia, Michigan (not far from Dearborn), where contractor A. O. Smith Company carried out the conversions. From now on, Ford alone would handle Shelby-Mustang promotion and development.

Times were indeed a-changin' for both Mustang and Ford Motor Company. As if to hint at things to come, Ford showed a wild Mustang-based concept at 1968 auto shows. Dubbed Mach 1, this low, sleek, and muscular fastback took familiar styling cues to extremes. Its enlongated nose was very aggressive, with a slim-section grille thrust ahead of pointy front fenders and rectangular headlamps. A louvered twin-scoop hood led back to a radically raked windshield matching a severe "chopped top" with much "faster" rear glass. Bodysides bore Mustang's signature character line, but fenders and wheel openings were prominently bulged to snug tightly around low-profile racing rubber on wide GT-40-style five-spoke aluminum wheels. A "ducktail" spoiler loomed over wall-to-wall taillamps and twin center-mount exhaust outlets. Other racing-inspired touches included a large, bright quick-release fuel filler behind each door window (the door glass was fixed) and working rear-brake cooling scoops. The rear window was combined with the trunklid, and the unit could be opened or closed by an electrohydraulic mechanism by flipping an interior switch.

At mid-model year, the GT-500s gave way to GT-500KR models with the new Cobra Jet engine boasting ram-air induction.

Designers must have had fun creating this one-of-a-kind showstopper, which looked for all the world like a Shelby Mustang on steroids. But did it also forecast the next showroom Mustang, which would have been mostly locked up when the Mach 1 was designed? And if Ford was mulling a bolder, brasher pony car, how would people take to it? No one could know, of course -- those pesky lead times again.

Still, we're pretty sure that Ford was well aware of one vital fact. Mustang was no longer the only horse in the stable, so future models would have to be even more carefully considered for the original to stay out in front. The pony car stampede might be slowing as 1969 beckoned, but the race was far from over.

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  • The 1968 Shelby Cobra GT-500KR was no mere Mustang. Check out this muscle car profile, which includes photos and specifications.