1970 thru 1981 technical support.
The second generation F-body cars were actually released as '1970½' cars, due to extensive delays in the design and production of the new body style. Both cars grew considerably, with fairly drastic changes in styling to match each brand's updated styling across the lineup. Only Pontiac received engine options in the 7.4 L range in the earlier years of the second generation - (454 cu in for Chevrolet is in technical manuals, but was never produced), 455 cu in for Pontiac. However, this engine option would be discontinued as emissions and fuel-economy restrictions made their production costs prohibitive. Performance continued to decline through 1981, as power levels dropped and weight increased.