Sonnax 258mm performance converter kit GM-RK-308 for GM Powerglide, TH350 and TH400 258mm applications allows builders to assemble a high performance converter with minimal effort. With the readily available GM 258mm converter cores, a variety of stall speeds can be built using different stator and impeller combinations.

• Fully machined cover with bushing installed
• Unit-specific design for hassle-free installation
• Oil flow grooves and holes increase fluid flow to keep converters running cooler
• Turbine hub features a larger flanged diameter to increase the strength rigidity of the turbine
• Clear, detailed instructions