In 1980, a very urgent need to meet EPA CAFE standards led to the creation of the 255 cu in (4.2 L) version, essentially a 302 with the cylinder bores downcored to 3.68 in (93.5 mm). Rated power (SAE net) was 115-122 hp (86-91 kW), depending on year and application. Cylinder heads used smaller combustion chambers and smaller valves and the intake ports were ovals whereas the others were rectangular. The only externally visible cue was the use of an open runner intake manifold with a stamped steel lifter valley cover attached to its underside, giving the appearance of previous generation engines, such as the Y-Block and the MEL. It was optional in Fox chassis cars including the Mustang and corporate cousin Mercury Capri, Thunderbird, Fairmont, and standard equipment in the Ford LTD. Poorly received thanks to its dismal performance and mediocre fuel economy, it was dropped after the 1982 model year, and is considered one of the worst modern Ford engines.