The Sonnax 10-clutch system increases lockup surface in GM Powerglides for significantly more torque capacity than modified OE drums. The drum kit includes 10 .060" frictions and 10 .060" thick , 24-lug steels, increasing lockup surface to allow significantly more torque than modified OE drums.
Sonnax 10-clutch drum kit with bearing 28756-08K is a complete drum kit that includes all high clutch related components, including a pump-to-drum bearing and shim, plus a pre-installed, PTFE-coated bushing. The Sonnax drum has material removed for the kit's bearing, allowing overall stack up to be .060" taller than an OE drum alone.
I've used several of the Powerglide 10-clutch drum kits in drag racing performance builds. The quality and reasonably priced product makes the choice to use over a stock or reconditioned drum a no-brainer.G. Carson