...the gear material depends on the material used to make the cam. The cam you have is what is called Austempered Ductile Iron, which is basically the same material a flat tappet cam would be made of, but it is heat treated instead of parkerized like flat tappet cam would be so that the roller profile can be ground onto it and so that the hardened roller wheels can ride on the lobes without damaging the cam. In most cases you will only find the need for a composite or bronze gear when you are using a race type solid roller cam which is made from a solid piece of billet steel. Hopefully that helps and there is a YouTube video on our channel that goes into a little more detail, but the best bet with a custom grind would always be to ask the manufacturer...