What we"ve got here is failure to communicate.
Typically your pin wears through the bushing and adversely wears on the axle pivot. This action mandates repair of the axle center section. Typically a machine shop operation with about $100/150 out of your pocket. When I did mine, I believe I had both bushings in possesion and requested the thicker one installed with the reasaoning it would take longer to wear through in the future.
Now once your out the cost of repair you will notice your axle has this wonderful hole in the center axle section and you will be greatly tempted to drill through the new bushing and add a grease zerk.
Grease attracts dirt and this will wear out your new bushing faster than the 50 years it took to wear out the original bushing.