This is the Federal-Mogul dual roller timing sprocket. It is important to remember Ford used several types of camshaft retainer plates and cam sprockets. You must check sprocket and retainer thicknesses before installation. You can check it as we did with a straight edge, with a perfect fit shown here. We fitted this engine with a Federal Mogul Mustang GT roller camshaft sporting 0.441-inch lift on the intake side. Real world? Smooth idle, good low-end torque.