TF727 727 High Torque Input Shaft and Hub. Designed for high torque engines with non lockup torque converter. Tested to 2,700 ft. lbs. of torque. The Shaft is made from 300 Maraging steel to withstand high fatigue and torsional loads. The hub is made from 4140 HTSR billet steel for additional durability. Shaft to hub splines are increased from the O.E.M. 28 spline to 35 spline for 25% more surface contact.