1973-’74 AMC Javelin AMX Buyer's Guide

Dyed-in-the-wool gearheads will tell you that the American muscle car ceased to be in 1972; that all Detroit pushed out thereafter were emasculated shells, badged-engineered attempts to play on the image of once great names. Most of these cars were even relegated to the option chart, turned from models to packages, and sprinkled with visual pizzazz while losing their real substance.

There's an element of truth to that scenario, but it isn't entirely accurate. History has proven that there was plenty of giddy-up left on the market for the taking during what has come to be known as the malaise era, with its emission regulations, big bumpers, and hefty bodies. Gearheads just had to look a little harder for the performance that remained. One place it could still be ferreted out was the pony car market, where some automakers, such as American Motors Corporation, continued to pacify the dwindling number of blue blood hot shoes with the four-seat Javelin AMX through 1974.

During 1973, both the four-barrel 360 and the 401 engines received a blast of power-inducing fresh air via their respective "Go" packages, which installed a cowl-induction hood.

In previous years, we've discussed the merits of the Javelin AMX—lovingly referred to as "humpster" due to the pronounced feature of its fender design—most recently in the April 2017 issue (HMM #164), which singled out the 1971-'72 versions. In that issue, we mentioned that the humped front fenders, as well as the tall rear spoiler and meshed grille, were incorporated into the 1971 redesign of the sleek fastback Javelin, thanks to input from racing legend Mark Donohue, who, along with team principal Roger Penske, had rocked the SCCA's Trans- Am racing community by switching to the Kenosha-based brand (Penske also began racing AMC Matadors in NASCAR's top division). Much like the winged Mopar's fender cutouts-and-covers, AMC's enhanced fenders homologated the design for competition, providing more space for meaty racing tires while lowering the front end, which ultimately reduced drag.

Penske/Donohue Trans-Am racing exploits aside, there was more to the street version than a unique profile, tri-color emblems, and that optional T-stripe. The Javelin AMX carried with it an option chart that could feed the need for an adrenaline rush through feet and fingers. Let's finally dive deeper into the 1973-'74 editions.

The hood disappeared for '74, which meant these engines were fitted with single snorkel air cleaner assemblies. Motorcraft was the choice of carburetor.

CHASSIS

Nearly all the redesign elements of the Javelin AMX that debuted in 1971 carried over to the 1973-'74 models. The unit-body platform retained its 110-inch-wheelbase, while the rear track still measured 60 inches. The front track, according to literature, was adjusted slightly, falling just shy of 60 inches (with V-8 engines) each year. Meanwhile, the basic "twin ball joint" front coil-sprung independent suspension system was also retained, along with the rear leaf spring system, all of which utilized firmer components than those found on lesser Javelins. Other standard features included the Dana Model 20 rear differential, available with a variety of ratios based on engine selection, unassisted 10-inch drum brakes on all four corners, and E70-14 raised-white-letter tires mounted on 14 x 6-inch slot-style wheels. The only change to this basic configuration came in 1974 when 11.2-inch vented front discs, with single-piston calipers, shifted from optional to standard equipment.

Speaking of options, the Javelin AMX continued to offer—as it had for the previous two years—a standalone handling package that provided upgraded springs and shocks, or the more desirable Go 360 or Go 401 packages, which automatically included heavy-duty suspension parts with other performance goodies, such as 15 x 7-inch slot-style wheels shod with E60-15 Goodyear Polyglas rubber, Twin-Grip differential and, in '73, front disc brakes. Power steering and brake systems were also optional upgrades.

ENGINE

One significant change that appeared in 1972 that carried forward into the 1973-'74 models, was the base Javelin AMX engine: a two-barrel carbureted 304-cu.in. V-8 that was rated for 150 hp and 245 lb-ft of torque through '74. Like its brethren we'll discuss momentarily, this "Gen-2" block was a thin-wall casting design. The 304 used a 3.75 x 3.44-inch bore and stroke, which managed an 8.4:1 compression ratio, while waste was pushed through a single exhaust system.

But that was just the beginning of the Javelin AMX engine choices, as three other V-8s were on the option chart, starting with the two-barrel 360. This was the former base engine of '71, which contained a larger 4.08-inch bore that complemented the 3.44-inch stroke. Touting an 8.5:1 compression ratio, its output was rated at 175 hp and 285 lb-ft of torque. When upgraded at the factory level with a dual exhaust system and a four-barrel carburetor, output jumped to a healthy 220 hp and 315 lb-ft of torque for the 1973-'74 model years.

The top of the heap was still the 401. This V-8 was produced with 4.17 x 3.57-inch bore and stroke dimensions and came only with a four-barrel carburetor and a dual exhaust system. Although compression had been lowered to 8.5:1, the 401's output in 1973 was listed as 255 hp and 345 lb-ft of torque. Though technically unchanged, the engine was downgraded for '74 to 235 hp and 335 lb-ft of torque, due to the elimination of the functional cowl-induction- style ram-air hood.

It should be noted that these engines were employed by a multitude of other AMC models during this timeframe, meaning that replacement parts are more plentiful than one might think. Additionally, the block's high nickel content made it robust, and able to withstand many miles of use along with occasional full-throttle blasts.

TRANSMISSIONS & DIFFERENTIALS

During this two-year stretch, in base 304 V-8 form, the Javelin AMX came standard with a floor-shifted three-speed manual, possibly surrounded by the optional center console. Yet it's more likely to find a 304-powered example fitted with a three-speed automatic, which mandated the console. The automatic was a Chrysler supplied A998 "Torque Command" unit. An AMX furnished with the two-barrel 360 would have mandated a Chrysler A727 equivalent. The same A727 unit was offered against the four-barrel 360 and the 401, both of which could also welcome a close-ratio Borg-Warner Super T-10 four-speed manual equipped with Hurst linkage and shifter.

As mentioned earlier, an open differential was standard issue, which could have been swapped for the Twin-Grip limited-slip unit. Ratios within each ranged from a highway friendly 2.87:1 gearset straight up to a quarter-mile conquering 4.10:1 ratio. Several of the shorter gears were available through the Go 360 and Go 401 packages.

BODY

Changes during this two-year stretch varied little from the initial 1971 redesign. Hallmarks of the fastback coupe remained the humped front fenders, tall rear spoiler, and previously unmentioned simulated T-top-style roof panel. The flush-mounted mesh grille with integral running lamps was carried over, but the tail panel changed to incorporate quad taillamps. A full-length body pinstripe was also standard, while AMX emblems adorned the grille, rear spoiler, and C-pillars. Exterior options, other than paint, were relatively few. Most notable were a front spoiler—mandating front disc brakes—and a large T-stripe on the hood, offered in just three colors. Another option was the cowl-induction hood associated with the Go 360 and Go 401 packages, but only through the '73 season. The Go packages also added a matte black finish to the tail panel.

Standard interior consisted of vinyl bucket seats and a contoured instrument panel with an engine-turned inlay. A Rally-Pac option upgraded the instruments, while vinyl upholstery could have been upgraded to cloth.

INTERIOR

Keeping the muscle car vibe alive were vinyl bucket seats, a three-spoke steering wheel, and an engine-turned contoured dash panel, all offered as standard equipment. Of note here was the optional Rally-Pac, which upgraded the instrument cluster with analog ammeter and oil pressure gauges, along with a combination tach/clock, and a 140-mph speedometer. The Rally-Pac was also available as part of either Go package. An option for 1973 was the "Cardin" trim, with special upholstery and other interior trim designed by Pierre Cardin. Choice of radio, air conditioning, and other assorted convenience options were also available, as was standard practice during the era.

ENGINE

Despite the displacement range offered in the Javelin AMX, the 304-, 360-, and 401-cu.in. V-8s were all based on the same block architecture. All had a thin-wall casting; however key internals varied in that the 304- and 360-cu.in. engines used cast crankshafts and connecting rods, while the stout 401 held a forged crankshaft and connecting rods. The carburetor supplier was Motorcraft. A historical footnote: The 401 remained in portions of AMC's lineup through 1979, while the 360 last appeared in the 1991 Jeep Grand Wagoneer.

TRANSMISSION & AXLES

Choice of engine dictated transmission and final drive ratio availability. The base 304/three-speed combination provided a standard ratio of 3.54:1 or optional 3.91:1, whereas a 304/automatic arrangement mandated a 2.87:1 gearset, or optional 3.15:1 ratio; this was the same setup used in conjunction with a two- or four-barrel 360/ automatic power team. Meanwhile, a four-barrel 360 or 401 mated with a four-speed provided a 3.54 or optional 3.91:1 ratio, while a 401/automatic combination first offered a 2.87:1 gearset, or optional 3.15 or 3.54:1 ratios.

A compelling interior option available only during 1973 was the Pierre Cardin package. When selected, seats, door panels, and the headliner wore black fabric featuring a red, silver, plum, and white stripe pattern.

INTERIOR

Standard Javelin AMX equipment included high-back vinyl bucket seats, a contoured instrument panel replete with a racy engine-turned applique, and sporty three-spoke steering wheel. Anything beyond the floor-shifted three-speed manual/ 304 power team stipulated the installation of a center console, save for the four-speed manual against the four-barrel 360 or 401-cu.in. engine. The 1973 Pierre Cardin version upgraded the seats and door panels with custom red, silver, plum, and white stripes against black material.

CHASSIS

AMC touted its "deep dip" rustproofing measures in literature, but we're all too familiar with the effects that snow-belt regions of the Lower 48 had on these cars. This generation of the Javelin AMX has known problem areas, including the inner fender troughs, wheelwells, the rear windowsill, and the base of each A-pillar. Mechanically, much of the suspension system secured to the 110-inch-wheelbase unit-body platform is serviceable, including shocks, front coil springs, ball joints, and so on. Drum- and disc-brake systems are also supported; front discs became standard for '74 models.

BODY

Although we mentioned it in prior coverage, it's worth noting again that, because of American Motors' tighter resources, engineers extended the use of several components from prior generation. Case in point: The 1971-'74 Javelin AMX used the doors, door glass, decklid, rear bumper and valance, rear window, and windshield from the previous generation Javelin. Seven continuous years of use means that these parts are somewhat easier to find. Other parts specific to the AMX, such as the rear spoiler and flush-mounted mesh grille, are harder to find.

PRODUCTION

From 1971-'74, AMC built 111,488 Javelins of all types, which included 15,961 AMX editions. If you think the bulk of the AMX output occurred during the 1971-'72 era, guess again—model production was as follows: 2,054 in 1971; 3,220 in '72; and another 5,707 and 4,980 examples unleashed in 1973 and '74, respectively. Production by engine type specific to 1973 editions, 1,134 had the base 304; 3,153 contained either 360; and 1,420 had a 401. For 1974, the engine breakout was as follows: 1,884 with the 304; 2,320 with a 360; and 776 with the 401.

PRODUCTION

1973 AMX AND JAVELIN

7379-8 (AMX)

304 V-8 ............................. 1,134

360 V-8 ............................. 3,153

401 V-8 ............................. 1,420

1974 AMX AND JAVELIN

7479-8 (AMX)

304 V-8 ............................. 1,884

360 V-8 ............................. 2,320

401 V-8 ................................ 776

PERIOD ROAD TESTS

* Test vehicle was a 1973 Javelin AMX equipped with E60-15 tires and test equipment.

WHAT TO PAY

* Add: 360-4V engine, 5 percent; 401 engine, 15 percent; factory air conditioning, 10 percent; four-speed manual transmission, $350 (average); Go package, $450 (average); Cardin package (1973 only), 10 percent

REPRODUCTION PARTS PRICES

Front fender, fiberglass ..........................................................................$520

Hood T-stripe kit .....................................................................................$169

Machine dash applique, w/o air ...............................................................$45

Spoiler (front) .........................................................................................$300

Spoiler (rear) ..........................................................................................$450

Taillamp gasket set ...................................................................................$25