300D Camshaft Wear Limits

[jjs300d]

What is the wear limit for the camlobes on a 1979 300D. The nominal measured maximum thickness accross each of the lobes is 1.520" to 1.525" on all of the lobes except cylinder number 1 intake and exhaust, and number 2 intake (the first three from the front of the engine). They measure 1.498", 1.490", and 1.504" respectively. There is obvious signs of wear on these and little or no wear on the remaining lobes. The car runs fine but does this wear mean we should replace the camshaft or is the wear acceptable for continued engine life. The mileage is 120,000.

Thanks
Jeff Stepek