Requires throttle body specific Stealth air cleaners (available separately) for 58 mm and 66 mm bodies Sealed, stainless steel throttle shaft with dual roller bearings for smooth operation and no air leaks One-piece throttle body/manifold design for easy installation and stock appearance Compatible with stock sensors, fuel rail and throttle cables Throttle bodies include hardened steel flanges and seals Black powder coat finish matches stock More air flow for improved performance Made in the U.S.A. Some S&S heads have additional material on the manifold surface to allow the use of a stock length manifold (405) on a 124" engine. If you are not sure which manifold should be ordered, check fitment with the stock manifold first.. THROTTLE BDY 66MM 124"06-