Funny, My Dad races a vintage 1970 mustang and WANTS smilin' axles for the negative camber. We rock crawlers end up with smiling axles and don't want them.
To get that smilin' axle syndrome and also to remove it takes a big torch and optionally a bucket of water. Heat up the housing deep red in a nice 4 inch + circle on the side you want to shrink and just let it cool naturally. Presto! Instant solid axle shaping. Want more bendage? cool it too fast with some water.
Yeah, I'm sure it is more art and flies in the face of safety/science what with all the aching molocules and embrittled, steel, but that is how they did it in the old days. and that is how my Dad does it now. *shrugs* I've only watched it being done.