The Sonnax 10-clutch system increases lockup surface in GM Powerglides for significantly more torque capacity than modified OE drums. The drum and piston accept 10 .060" frictions and 10 .060" thick steels, increasing lockup surface to allow significantly more torque than modified OE drums.
Sonnax 10-clutch drum, hub and piston kit with bearing 28756-16K includes the three essential components for building a 10-clutch drum assembly, plus a pump-to-drum bearing and a a shim. The Sonnax drum has material removed for the kit's bearing, allowing overall stack up to be .060" taller than an OE drum alone. An alternative kit, 28756-15K, is the same overall height as OE, but does not include a pump-to-drum bearing and shim.
Contact a Sonnax Parts Distributor.