Ford C4 Transmission Maraging Billet Input Shaft 24/26 Spline Combination C4 Billet Steel 300 Maraging Input Shaft Made from high strength 300 Maraging for superior fatigue and fracture resistance. Shaft is made to handle high horsepower applications in cars using performance enhancers such as turbochargers, nitrous, superchargers as well as for competition off-road trucks. Shaft comes in the conventional 24x26 spline combination and installs as easy as the stock C-4 input shaft. Teamed up with the TCS C-4 billet steel drum this becomes an unbeatable combination.