Drum explosion...

The sprag's outer diameter is splined and so is the case. In stock form it is held in place by a set screw and the splines. If splines/setscrew/elements fail, the front drum will spin twice the engine rpm. The stock drum is pressed powdered metal. It will explode at 9000 rpm (4500 engine rpm). The bolt-in sprag with the additional elements (rollers) will help prevent this and the billet drum won't explode.

Chris is right and knows his stuff, that's why I recomended him to you. Chris was kind enough to supply parts and knowledge to me on my 4x4 727 build and I couldn't happier with his service. Like I said before, I've seen his trans's make pass after pass after pass here at Bandimere raceway on a 10.4 second car. BTW, that car and driver won ET class last time I saw it.

Chris, thanks for all your help! The trans works great and shifts good and tight.