ironworker40
NYC Ironworker
Some axles have wedges that go on bolts to lock axle in. Its been years so I have no idea of what sizes they are available in but you could easily taper hole on axle to use them if you can find the correct size.
http://www.quad4x4.com/qu40577.html
These say dana 60 and 7/16
http://www.quad4x4.com/qu40577.html
These say dana 60 and 7/16