AMC AMX 390

AMC AMX 390

The 1968 AMX 390 represented the most powerful version of American Motors' audacious two-seat muscle car. While the AMX was available with smaller engines, the 390 cubic-inch V8 transformed it from a sporty cruiser into a genuine performance machine capable of competing with the Big Three's offerings.

The 390 V8 (6,391cc) was AMC's largest engine, producing 315 gross horsepower at 4,600 rpm and 425 lb-ft of torque at 3,200 rpm. Fed by a Carter AFB four-barrel carburetor and breathing through a cast-iron exhaust manifold into dual exhaust pipes, the engine delivered its power with a deep, authoritative rumble. The 390 was available with either a Borg-Warner T-10 four-speed manual gearbox or a BorgWarner automatic.

The AMX's compact dimensions — just 97 inches of wheelbase, 7 inches shorter than the Javelin — gave the 390-powered version a power-to-weight ratio that was competitive with contemporary Corvettes and Shelbys. The car weighed approximately 1,430 kg, and the 390 engine made it capable of sub-7-second 0-60 mph times.

The suspension was typical of the era: independent front with double wishbones and coil springs, and a live rear axle on semi-elliptic leaf springs. Optional upgrades included stiffer springs, a handling package with larger anti-roll bars, and limited-slip differential — essential for managing the 390's considerable torque.

The AMX 390 was a car that punched well above its weight, both literally and figuratively. AMC may have been the smallest of the American manufacturers, but the AMX proved that good engineering and a willingness to take risks could produce a car that stood shoulder to shoulder with the establishment.

Production of the 390-equipped AMX was a subset of the total 6,725 units built for 1968, making 390-powered examples relatively uncommon and increasingly collectible among muscle car enthusiasts.