Kevin is right. Warren makes their oil and has done so for a long time. It's the Sam's Club gasoline that's hit or miss.

Tommy, the CCCA has high ZDDP oil made especially for antique cars.

Classic Car Motor Oil 1600ppm ZDDP

https://inrccca.org/product/classic-car-motor-oil/


1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)