don't know about new axles, never broke one - a buddy has
a 55 w/ 427 and the stock axle works fine lifting the front wheels!
the yoke should be available, or there's lotsa used around, and all the bearings are on the shelf - find a good rear end shop and everything will be available - I've talked to a place
in Vancouver BC that can fix ya up with near anything including the 3.38 gearset, they may have axles too
Bill