Eliminate concerns of input shaft and drum breakage in high performance applications with this TCI® 4L60E LS HD Shaft & Drum Assembly. The input shaft is made from a heat-treated, billet 300M material with a higher yield strength that resists breakage and results in less shaft twisting than OEM material. Rolled splines increase the strength and density of the material in the splined areas; rather than removing material, the splines are actually compacted, which causes the material to be more dense in this area. The sleeved drum is made from ultra-strong 4130 steel for superior strength and durability. In addition, a Beast sunshell stops any chance of sunshell breakage. The combination of 300M input shaft, 4130 steel sleeved drum and Beast sunshell make this assembly the ultimate upgrade for virtually any high horsepower application that uses a 4L60E transmission.