Hi, you blamed this issue on the PO but failed to say what he did.
It occurs to me that cam bearing problems might occur on a warped head especially one that has been cut back flat rather than un-warping it with a plate and heat to stress relieve.
A cut back flat head would likely leave the cam bearings out of alignment.
Ken Geiger, Toronto
1965 GTA, RHD, Stradale
ex- 1965 GTA, RHD, Corsa, Trans/Am 66-72
1964 Sprint GT, B-Sedan in 70's
1970 Giulia Super (CDN Spec)
1976 1600 GTj (Italian Spec)
1966 Harley Sprint (Aermacchi) 250
2000 Catalina 320, Hull #765 Northern Dream
2001 BMW Z3 3.0i