ATI's Outlaw Lock-Up Converters lock up in just .03 seconds when used with ATI’s SuperCase and Pump. Standard welded units provide 0% slip for up to 2800 HP while the Bolt Together Lock Up Converter will provide 0% slip all the way up to 4500HP! Both converters feature 5-axis billet aluminum back cover, dual o-ring sealing, optional Nissan style pump and multiple stator designs. A bronze pilot option is also available.
Two years on and I am still unconvinced. I am still asked the two nut question but I always tend to recommend other more modern ways of locking the threads. I think that the reasons that I am not easy with the method is that it is too reliant upon the skill of the person tightening the joint. There is also the amount of backlash in the threads (you could strip the threads of the small nut if it was a tight fit) and the preload will be down on what it could be as well.