I have a 283 sbc from a 1966 Chevelle that had been overhauled to stock specs (installed in my '57 Willys CJ5). It is running 305 heads and has 1300 miles on it so far. As far as oil goes, do I need something like this oil with added zync or will any oil suffice? I currently have Mobil 1 synthetic 10w-30 in it. Oil pressure runs around 40 cold idle and 12-15 hot idle up to 30-ish hot around 2500-300 rpm. Should I change? I live in NC and it is hot during the summer and can be cold in the winter.

AMSOIL Synthetic Motor Oil and Engine Oil