I was given a box full of mazdaspeed miata head components.. mainly the valves/springs/retainers.

My question is this... what are the stock motor valve dimensions?

Is this 1.8L valve "oversized" compared to the 1.6l miata motors?

Are the springs similar dimensions with maybe a stiffer rate?...

Help me figure out if these are garbage fodder... or if I should toss them into a spare 1.6l head when I build it for fun.