only, Monzas sold in California and high altitude areas met the stricter emissions requirement by substituting a version of the V8 engine with a two-barrel carburetor tuned to just . The Monza 2+2 and its Buick and Oldsmobile variants feature GM's first use of a torque arm rear suspension, also adopted for the 1975 Cosworth Vega introduced mid-1975, and later, all 1976–1977 Vegas and Pontiac Astres. The basic design was also incorporated into GM's third and fourth generation F-bodies, the Chevrolet Camaro and Pontiac Firebird. In April 1975, the Monza Towne Coupe was introduced — a notchback body-style with a conventional trunk featuring different sheetmetal than the 2+2 hatchback, but sharing its windshield and front fenders. It features single round headlamps, instead of the dual rectangular headlamps on the 2+2. The Towne Coupe was offered in response to the sales success of the Ford Mustang II notchback coupe and its luxury version, the Mustang II Ghia. The Towne Coupe is shorter and lighter than the 2+2 and has slightly more rear head room. A lower priced "S" version of the 2+2 hatchback was introduced mid-year. It featured as standard the Vega one-barrel engine with a three-speed manual transmission. The sport suspension, full console, sport steering wheel, day/night rear-view mirror and wheel opening moldings were deleted on the "S". The Chevrolet Monza 2+2 won Motor Trend magazine's Car of the Year award for 1975. Model year changes The 1976 four-cylinder engine, as used in the Vega, got some refinements. Named "Dura-built 140", it features quieter hydraulic lifters eliminating valve adjustments. The basic four developed 70 horsepower, but two-barrel carburetion increased the rating to 84. The 1976 model was the introduction of Chevrolet's new 5.0 liter (305 CID) V8 engine with a two-barrel carburetor generating at 3,800 rpm, but only for California and high-altitude Monza customers, and replaced the 350 V8. The 262 was again the optional engine in 49 states. A redesigned dashboard replaced the Vega-derived one. A mid-year option for 1976 was a "Sport" front end available for the Towne Coupe, which featured the 2+2's polyurethane front end and quad headlamps. The Monza Spyder equipment package was introduced in 1976 for both the 2+2 hatchback and Towne Coupe. It featured a two-barrel carburetor version of the four-cylinder engine as standard, a floor console, sport steering wheel, F41 suspension with larger front and rear stabilizer bars, and special shock absorbers. This