GM TH400 Billet Aluminum Center Support W/ Billet Oversized Intermediate Piston Speedmaster starter shim kits are

Speedmaster starter shim kits are designed to ensure that you have the proper gap between the starter and flywheel

Uses OEM support bushings

less intake charge contamination

and extended high gear splines to the oil ring

Speedmaster valve guides are constructed from high-quality bronze for durability and wear

GM TH400 Billet Aluminum Center Support W/ Billet Oversized Intermediate Piston Speedmaster starter shim kits areIf your TH400 transmission is being used in high power applications, you'll need to look at every area of the transmission to boost your performance. It is highly recommended for competition applications.