Silver Bullet throttle body spacers create turbulence in the air flow at the point just prior entry into the engine increasing horsepower, torque and improving throttle response and fuel efficiency. Silver Bullet throttle body spacers are constructed out of durable T-6061 billet aluminum and using a unique serrated/helix entry to create turbulence at the manifold while eliminating the annoying whistle found in other helix only throttle spacers. PartNumber : afe46-33011 Description : Silver Bullet Throttle Body Spacer 2011 Ford F-150 Harley-Davidson Edition V8.6210cc Air Intake Systems::Throttle Body Spacers 2011 Ford F-150 Platinum V8.6210cc Air Intake Systems::Throttle Body Spacers 2010-2014 Ford F-150 SVT Raptor V8.6210cc Air Intake Systems::Throttle Body Spacers 2011 Ford F-250 Super Duty King Ranch V8.6210cc Air Intake Systems::Throttle Body Spacers 2011 Ford F-250 Super Duty Lariat V8.6210cc Air Intake Systems::Throttle Body Spacers 2011 Ford F-250 Super Duty XL V8.6210cc Air Intake Systems::Throttle Body Spacers 2011 Ford F-250 Super Duty XLT V8.6210cc Air Intake Systems::Throttle Body Spacers 2011 Ford F-350 Super Duty King Ranch V8.6210cc Air Intake Systems::Throttle Body Spacers 2011 Ford F-350 Super Duty Lariat V8.6210cc Air Intake Systems::Throttle Body Spacers 2011 Ford F-350 Super Duty XL V8.6210cc Air Intake Systems::Throttle Body Spacers