Product details:

ATI Performance Products ATI357050: Input Shaft, Torsional, 4340 Forged Steel, Chevy, TH350, Powerglide Spline, Each - ATI torsional input shafts work like a torsional spring bar--twisting and returning to totally eliminate breakage, while reducing shock loads to the gear train. They are manufactured from top-quality 300M or 4340 forged steel for maximum durability. Available for GM Powerglide or TH400 splines, these ATI torsional input shafts will add some reliability to your drivetrain.