When Jack Roush pulled off the cover and unveiled the new 510-horsepower ROUSH P-51ATM Mustang at the SEMA Show in October, it took just moments before the telephones started ringing at the offices with dealers and consumers clamoring to get hold of the muscle car.

Although the ROUSH order bank isn't scheduled to open to authorized Ford dealers with final pricing until January, 2008, the post-announcement interest was enough for ROUSH management to re-assess the total number of ROUSH P-51ATM Mustangs that will be released to the public. Consequently, ROUSH Performance has decided to increase the production run to 151 units when these start build, anticipated to be the first quarter of 2008. It was previously announced that the production volume would be limited to 100 units.

"Certainly we anticipated that the ROUSH P-51ATM Mustang would be a popular car and sell quickly to our dealer base," said Joe Thompson, general manager of ROUSH Performance. "But I must say that we were a little surprised at just how fast the demand grew for this car so we worked with our suppliers to make ensure that an increased volume would be possible and can now announce that there will be 151 vehicles produced next year."

The ROUSH P-51ATM is easily the highest horsepower Mustang that the company has ever produced, and represents the first time that internal engine components have been upgraded by ROUSH technicians in their Livonia, Mich., facility.

The stock Ford 4.6L, 3V engine will see a rebuild of several of the functional internal components, including 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 ROUSHchargerTM supercharger system.
  

Additional alterations include a custom aluminum upper and lower intake manifold for the high capacity air-to-water intercooler and ROUSHchargerTM. ROUSH installs a custom fuel rail and high-flow fuel injectors, a high-flow capacity fuel system, as well as a dual electronic throttle body.