Check camshaft end play and distributor height. (intake manifold) and the oil pump. High oil pressure will put more stress on the distributor gear.
The cam can be repaired depending on what core it is.
"Street roller" cams have a pressed on section on the end. The distributor gear and last bearing journal are cast iron (like a flat tappet cam) and are pressed onto the end of a roller billet (street roller) if Jones Cams cannot repair it contact Crane Cams. The block can be modified to increase/direct oil flow to the cam distributor gear.