Amsoil now makes a Zinc Added Synthetic:
Z-Rod 20W-50
They say 'High Zinc', and I did find a dealer quote:
'The TSB lists that these oils have zinc – 1440 ppm, phosphorus 1320 ppm'
So knowing Amsoil's reputation, this may be a nice option
Edit: Found the TSB:
Amsoil Flat Tappet and Lobe Lubrication TSB
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1996 Z-28: Bolt-Ons, Harwood Cowl Hood, 18" Black Z06s
2005 Subaru Legacy GT - Stage 2 - My DD
2012 Audi S4 - The Wifee's Ride (Wait - the wife drives the fastest of the stable?
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