The ROUSH Performance P-51A™ Mustang is easily the highest horsepower Mustang that the company has produced at the time of its release, and represents the first time that internal engine components have been upgraded by ROUSH technicians in their Livonia, Mich., facility. It was determined that the only way to give the P-51A™ moniker its due was to completely break into the 4.6L, 3V and rebuild several of the functional internal components, which include a forged steel eight-bolt crankshaft, forged aluminum pistons with increased dish to lower the compression from 9:8 to 8:6, and forged steel H-Beam connecting rods. These upgraded parts were necessary for the stock Ford engine (which comes with 300 horsepower from the factory) to be able to withstand the additional power generated from the newest iteration of the legendary ROUSHcharger™ supercharger system.
The new ROUSH P-51A™ engine has a preliminary rating of at least 510 horsepower and 510 lb.-ft. torque. It is anticipated that final figures may even be slightly higher than this when final testing and calibration is approved by the ROUSH engineering staff.