Ford has been rolling out a lot of factory racers lately. Cars in white, as they are known. Limited runs aimed at the bracket drag crowd and other denizens of the quarter miles strips scattered across the land. Here's Ford's latest: The 2010 Mustang Cobra Jet, and it has an optional aluminum block. Last year, Ford did a 50 car production run of 2008 Mustang Cobra Jets. As you'd imagine, the program was a massive success with the entire run of cars selling out before production even started. The factory-built drag cars not only proved their worth on the FoMoCo balance sheets, but also on the nation's 1/4 mile tracks this year. So, doing another limited run of the Cobra Jets is a lead pipe cinch. Rolling