That is in the upper range on both limits for PPMS,The best budget oil I found was Valvoline Vr1 20/50.It holds about 1200 phosfo/1400 zinc.About five bucks a qt.
My post was a bit tongue in cheek. The fact that T&D insisted that the shaft damage was due to low zinc levels - in Mobil 1 15W50 - and that high zinc levels are really needed for roller rockers....