This knock down, drag out, rock-n-roll King of the Hill cam is our top dog.  The 251 duration may cause blurred vision at idle and .630" lift give the potential for broken drivetrain parts.  Intended for all out custom built race engines, this cam is not recommended for a daily driver.  With an aftermarket manifold, such as out sheet metal intake, on a 427ci with 11.75 to 1 compression this cam can exceed 600+ horsepower.