TCS Billet Steel Ford C4 Forward Clutch Drum C-4 Steel Forward Clutch Drum This C-4 Forward Drum is a marketplace FIRST! Precision machined from 4140 HTSR billet steel providing superior strength and durability. The drum comes with one .095" thick steel plate for clearance adjustment and, one pressure plate. Made for drag racing and off-road applications. This drum can accommodate 5 frictions.