Hi Cobra 29,
I agree I wasn't totally clear about this, so here goes again
Roller cams are almost always steel cams, either solid or hydraulic roller lifters are used.
Flat tappet cams (either solid or hydraulic flat tappet cams) are non-roller lifter cams made of cast iron.
For the distributor gear, use a steel gear with a steel cam, a cast iron gear with a cast iron cam.
A bronze gear may be used with either cam (it's made of softer metal than either of these) but must be checked every few thousand miles for wear, as it will not last anywhere near as long as the steel or iron gears.
Hope this clears that up
The cam mfr can tell you what material your cam is made of and most can sell you the appropriate material gear for the distributor.
Tom