Looks like DynoTech Engineering (Troy, Michigan) not only can they shorten and weld an AMMC driveshaft - they have many replacements in stock for most hipo vehicles. (Hey Marty - they have them for your truck !!) Started as a GM research lab.
25% stronger then same size chrome moly steel ??? wow. I don't know what that means - but I want it !!! LOL
http://www.dynotecheng.com/