at 4200 rpm Torque at 2600 rpm Compression ratio 8.5:1 Output for 1982-83 models (net): Horsepower at 4000 rpm Torque at 1800 rpm Compression ratio 8.5:1 Engine dimensions: Intake valve diameter Exhaust valve diameter Connecting rod length Deck height Bore Stroke VAM Javelin (1971–1973) U.S. equivalent - AMC Javelin VAM Classic DPL (1972–1976) U.S. equivalent - AMC Matador Sedan VAM Classic Brougham (1972, 1974–1976) U.S. equivalent - 1972 AMC Matador hardtop and AMC Matador Brougham coupe VAM Classic AMX (1974–1976) U.S. equivalent - AMC Matador X coupe VAM Pacer (1976–1979) U.S. equivalent - AMC Pacer coupe VAM Pacer X (1979) U.S. equivalent - AMC Pacer X coupe VAM American Rally (1976–1977) U.S. equivalent - AMC Hornet X sedan instead of hatchback VAM American Rally AMX (1978–1979) U.S. equivalent - AMC Concord AMX hatchback VAM American GFS (1977–1982) U.S. equivalent - AMC Hornet DL two-door sedan plus AMC Concord DL and Limited two-door sedans VAM Camioneta American Automática (1977–1978) U.S. equivalent - AMC Hornet DL wagon and AMC Concord DL wagon, both with automatic transmission VAM Camioneta American DL (1979–1983) U.S. equivalent - AMC Concord DL and Limited wagons VAM American 06/S (1979) U.S. equivalent AMC Concord two-door sedan, high-performance limited edition VAM American ECD (1980–1982) U.S. equivalent - AMC Concord DL and Limited four-door sedans VAM Rally AMX (1980–1983) U.S. equivalent - AMC Spirit GT coupe, standard version VAM Rally GT (1980–1981) U.S. equivalent - AMC Spirit GT coupe, high-performance version VAM Rally SST (1981) U.S. equivalent - AMC Spirit Limited coupe VAM Lerma (1981–1982) VAM Jeep Wagoneer (1972–1983) U.S. equivalent - AMC Jeep Wagoneer Renault/VAM Jeep Grand Wagoneer from 1984 through 1986 (U.S. equivalent - Jeep Grand Wagoneer) 4.0 The engine was developed by AMC in just 26 months using many off the shelf components while featuring, among others, additional strength, improved combustion chamber, port setup, and cam profile. The total weight of the new engine was , only one pound more than the 258 six despite its heavier components and parts. For example, the cast aluminum valve cover featured 15 bolts, the industry's most, to achieve a positive seal. The new engine, which was introduced in 1986 for the 1987 model year, was a further evolution of AMC's 258 six. It had a bore and a stroke giving it a displacement of . Connecting rod length was 6.125" - similar to the discontinued 199 which was phased out