I've been researching piston rings for a build, and since I can't get OEM 82mm, I want something as close to OEM style as possible. I believe the engineers at Honda know more about engine building than I do, so I may as well follow their lead when rebuilding an engine for street use.

Are OEM rings regular gray iron, moly coated, nitrided? Someone has to know.

I can get Hastings moly coated or NPR nitrided rings. I'm not sure if they are gas or plasma coated however.