273 hp specs

A search found the following H.P. information at http://en.wikipedia.org/wiki/Chrysler_LA_engine#273_V8

273 V8
The 273 (4.5 L) was the first LA engine, introduced in 1964 and offered through 1969, rated at 180 BHp. It had a 3.625 in (92 mm) bore and 3.31 in (84 mm) stroke. It had a mechanical solid lifter valvetrain until 1968 when hydraulic lifters were introduced. A special version was also available in 1966 only - it used a 0.500-inch (12.7 mm) lift solid-lifter camshaft, fabricated-steel-tube exhaust, and a Holley 4-barrel carburetor, producing 275 horsepower (1 hp/cu in). It was available in the Dodge Dart only, and the car so equipped was called the "D-Dart". A 235 hp (175 kW) version with a less aggressive camshaft and without the tube headers was available on regular production Darts, Valiants, and Barracudas from 1965 to '67, it was standard only in the Barracuda Formula S model.