[Mike Taylor 3601]

Bronze must be used on billet geared roller cams,but can also be used on cast and ductile iron cores.
Can't use cast or steel gear(regular) on billet though,there are rollers that have gears on them that can have regular gear ran on them,those cams can be identified,if you look @ cam you will see where on rear bearing journal and gear are made separately and then installed on cam.
In the last few years they have came out with a few different gears materials,I have'nt tried any of them,I have just stuck with bronze,have good service with them so have'nt looked else where.
In case some don't know MSD maybe some others also have gears that are available oversizes,that will reduce backlash if needed.
Mike Taylor 3601