I just went to the factory and picked up two Avon Progear chains for my boat motors. The gears are made in house in LaGrange IL. They use the Rolon / Renold Gold chain.
I noticed while I was there that they make the timing sets for Edelbrock and Manley as well. Useless trivia fact: Avon / Pro Gear is directly across the street from Billet Specialties.