Mr. Gasket Ford Intake Manifold Bolts are heat-treated to Grade 5 specs and zinc-plated to resist rust and corrosion. Designed specifically for small-block Fords, these durable 2.00-inch-long 5/16-18 bolts are a perfect fit for tight spaces, have extra-thick parallel-ground flat washers for a smooth, consistent torque, and come in a set of 12.