Rocker Arm Asembly

[Dave Bunker]

I ran into an indy MB shop today. The svc mgr told me that right around 180k miles the metal alloy starts wearing off the surface of the rocker arm causing the cam lobs to wear down. He says it's common in 420's. He says a cam job is $2000 and replacing the rockers is around $500. I wanted some feedback on this, before I look any further. Does anyone have any opinions on this.