anything CAN be done, but at a cost. yes you can make the 6 speed from the challenger go into a magnum. but you would probably need to transfer significant amounts of floor pan, and possibly sections of firewall, large quantities of electronics, and driveline from a challenger. if i ever get to a point where i can afford another project car, i might get a mag and drop a TR6060 into it. would have to be an 08 to begin with, will make doing a lot of the work simpler.