1972 was the last model year for the mid-sized Buick Skylark. During this model year many pollution controls were added to the engines, Compression was lowered, engines had to accept leaded and unleaded gas, and spark timing was retarded (no vacuum advance in lower gears) while driving in lower gears to reduce emissions. For 1972, the base Buick Skylark used the 350-cubic-inch V8 with the 2-barrel Rochester carburetor (now putting out 145 horsepower) as standard equipment. A new federally mandated system to calculate power was put into effect that year, and the actual engine performance was probably comparable but slightly lower because of pollution controls in the 1972 model year to the that was listed for the previous year. The Skylark 350 now used a version of the same V8 engine as the base Skylark, but with a 4-barrel Rochester carburetor that generated .