Do z20 parts crossover to z18?

Hi guy and gals,

Thanks for the great help in the past.

Currently, I'm planning a major overhausl of my 1979.5, 720 Datsun, z18 pickup. Problem is, most of these came stock with a z20 engine, and I am having a real hard time finding any z18 parts. Wondering if z20 rebuild parts like valves, valve seals, valve springs, pistons, rings and bearings will crossover to the z18.

Any advice would be greatly appreciated.

Best to all,

G2L