Mustang put on pounds and inches for ’67, so the Shelby GT-350 did too. But that wasn’t the half of it. Ford now offered its big-block 390 V-8 as the top Mustang performance option. Typical of the man, Carroll specified the physically identical 428 engine for a second Shelby called GT-500. It was a popular move, the newcomer outselling its smaller-capacity stablemate two-to-one.
Still, performance began taking a back seat to styling and luxury with the ’67s, because that’s where the money was spent. Ford was still spending it, of course, but was now more intimately involved with the Shelbys -- and more determined that they turn a profit.
Because Mustang was heavier for ’67, and with customers wanting a more manageable Shelby, power steering and brakes became mandatory Shelby options. Mustang’s newly reworked ’67 interior was little altered for the Shelbys, though they continued with several unique touches: distinctive racing steering wheel, additional gauges, and a genuine roll-over bar with built-in inertia-reel shoulder harnesses. Comfort and convenience options proliferated: air conditioning, tinted glass, tilt steering wheel, and more.
Outside, Ford’s Chuck McHose and Shelby-American’s Pete Brock styled a new fiberglass nose to match Mustang’s longer ’67 hood, with a “big-mouth” grille bearing twin center-mount high-beam driving lamps (since moved outboard on some cars to comply with headlight-spacing regulations). Scoops were everywhere -- hood, lower bodysides, sail panels -- all functional and, of course, larger. Out back, a special trunklid with integral spoiler appeared above wide taillamp clusters purloined from the new Mercury Cougar.
All these touches plus Mustang’s new full-fastback styling made the ’67 Shelbys handsome, fast-looking cars. Alas, Shelby GT-350 performance sagged under the weight of all the new fluff. Its horsepower was ostensibly the same as before but surely less in actuality, as the steel-tube exhaust headers had disappeared.The new GT-500 was quick, but curiously disappointing. Carmakers began using more conservative horsepower ratings for ’67 as a sop to insurance companies. The Shelby’s 428 had an advertised 335, though again it was probably more. Car and Driver, whose test car took 6.5 seconds 0-60 mph, said that while the 428 “isn’t the Le Mans winner,” the GT-500 “does with ease what the old [GT-350] took brute force to accomplish.” But Road & Track, which recorded 7.2 seconds for the same sprint, said the Shelby GT-500 “simply doesn’t have anything sensational to offer . . . . A [standard] Mustang with the 390 cu. in. engine option does as well.” As ever, Shelby had an answer: an optional 427 -- which was the Le Mans engine -- rated at 390 bhp. Still, not many were ordered.
Dearborn’s control over the Shelby-Mustangs became total for ’68. Production was moved from Los Angeles to Michigan, where stock Mustangs (from Ford’s Metuchen, New Jersey plant) were converted into Shelbys by the A.O. Smith Company under contract. The fastbacks gained convertible companions with built-in roll-over hoop, and all four models sported a full-width hood scoop, new hood louvers, a larger grille with square running lamps (not driving lights), sequential rear turn signals, and minor trim changes.
With federal emissions limits in force, the Shelby GT-350 was switched to Ford’s newly enlarged 302-cid small-block -- and lost a lot of power. However, the Paxton supercharger option returned from ’66 to add about 100 horses, though it, too, found few takers. The Shelby GT-500 initially retained its 428, now at 360 bhp. A few, however, got ordinary 390 V-8s. This probably stemmed from a shortage of 428s due to an engine-plant strike, but buyers weren’t told about the substitution, which was nearly impossible to spot.
Mid-year brought some redress, however, in the Shelby GT-500KR (for “King of the Road”). This had the new Cobra Jet engine, basically the existing 428 with big-port 427 heads, larger intake manifold and exhaust system, and an estimated 40 extra horses. Ford also tossed in wider rear brakes.
Shelby production rose for the fourth straight year in 1968, but would go no higher. The press mostly yawned at the plusher ’68s, and Ford made no effort to race either the ’67 or ’68 Shelbys. Not that they’d have been competitive. They’d grown too big, too soft, too heavy -- not at all the race-bred stormers their predecessors had been. And Ford only managed to dilute their appeal further with Shelbyesque showroom Mustangs like the ’68 GT/CS (“California Special”) notchback. With all this, the Shelby-Mustang wasn’t dead by the end of ’68, but it didn’t have lone to live.