727-518-618 Billet Steel Front Drum in Big Piston. • Stronger, more reliable and safer than the O.E.M. cast iron drum – Ideal for street use • Will hold 5 thick or 6 thin friction plates versus 4 in the O.E.M. unit • 55% MORE Piston Apply Surface Area! This results in double the clamping force needed in third gear – Just what you need for high performance and EXTREME applications • Engineered with dual oil apply passages for even piston apply • Kit comes with a precision EXTRA-LARGE CNC machined billet aluminum piston.