Speedmaster PCE602.1009 GM 4L80 Stock Spline 300M Automatic Transmission Input Shaft [34670-01]

The Speedmaster PCE602.1009 is a high-performance input shaft designed specifically for GM 4L80 automatic transmissions. Machined from 300M alloy steel — a material renowned for its exceptional tensile strength and toughness — this stock-spline input shaft delivers superior durability over the factory unit, making it an ideal upgrade for high-horsepower and high-torque applications.

Engineered as a direct stock-spline replacement for the GM 4L80, this input shaft installs with confidence using the factory spline count for straightforward fitment. Whether you're building a street/strip machine or a dedicated performance vehicle, Speedmaster's 300M input shaft provides the reliability your drivetrain demands under demanding conditions.