The AMC Javelin was restyled for the 1971 model year. The "1980-looking Javelin" design was purposely made to give the sporty car "individuality," even at "the risk of scaring some people off." The second generation became longer, lower, wider, and heavier than its predecessor. The indicated engine power outputs also changed from 1971 to 1972-74. Actual power output remained the same, but the U.S. automobile industry followed the SAE horsepower rating method that changed from "gross" in 1971 and prior years to "net" in 1972 and later years.
The new design incorporated an integral roof spoiler and sculpted fender bulges. The new body departed from the gentle, tucked-in look of the original. The media noted the revised front fenders (originally designed to accommodate oversized racing tires) that "bulge up as well as out on this personal sporty car, borrowing lines from the much more expensive Corvette." The new design also featured an "intricate injection moulded grille."
The car's dashboard was asymmetrical, with "functional instrument gauges that wrap around you with cockpit efficiency". This driver-oriented design contrasted with the symmetrical interior of the economy-focused 1966 Hornet (Cavalier) prototype.
AMC offered a choice of engines and transmissions. Engines included a 232 cu in (3.8 L) I6 and a four-barrel 401 cu in (6.6 L) AMC V8 with high compression ratio, forged steel crankshaft and connecting rods engineered to withstand 8000 rpm. The BorgWarner T-10 four-speed manual transmission came with a Hurst floor shifter.
From 1971 the AMX was no longer available as a two-seater. It evolved into a premium High-Performance edition of the Javelin. The new Javelin-AMX incorporated several racing modifications and AMC advertised it as “the closest thing you can buy to a Trans-Am champion.” The car had a stainless steel mesh screen over the grille opening, a fiberglass full-width cowl induction hood, and spoilers front and rear for high-speed traction.
The performance-upgrade "Go Package" provided the choice of a 360 or 401 4-barrel engine, and included "Rally-Pac" instruments, a handling package for the suspension, “Twin-Grip” limited-slip differential, heavy-duty cooling, power-assisted disc brakes, white-letter E60x15 Goodyear Polyglas tires on 15x7-inch styled slotted steel wheels) used on the Rebel Machine, a T-stripe hood decal, and a blacked-out rear taillight panel. The 3,244-pound (1,471 kg) 1971 Javelin AMX with a 401 cu in (6.6 L) was able to complete the quarter-mile in the mid-14 second range at 93 miles per hour (150 km/h) on low-lead, low-octane gas.
Honoring the 1971 and 1972 Javelin Trans-Am victories, a special "Trans-Am winner" decal for the front fenders was available for any trim level.