they are still using the "testing under load" method...they want the horsepower at the crank to be realistic, and i believe that now engines are tested with the cats and such, which they didnt have back then.

however, alot of cars actually dyno higher than stated. several sources, such as either car and driver or motor trend (one of the big magazies) as well as one of the mopar magazines, have dyno'd the 6.1L, and it actually puts out power in the 46X range...