I have read time and again about how roller camshafts require a bronze gear for the oil pump drive. Can anyone help me to understand why? Did the factory cams require this? I don't remember anything different in the 3 or 4 roller small blocks that I have pulled apart.
The reason for the softer oil pump drive gear had to do with dissimilar metals, and that its easier to change a worn oil pump drive than the cam. Why didn't the aftermarket make them out of the same metal as with flat tappet cams? If the bronze gear wears, what about the debris? Can we trust the oil filter to screen all of it from the oil?
I ask this because I have considered switching to a roller cam to insure that I won't have to swap camshafts again unless I want to. Cam failures are a real pisser.

It all depends on the material used to make the camshaft. You can buy hyd roller cams for SB motors that use the factory oil pump gear. As far as I know all of the Mopar solid roller cams require a bronze gear but it is possible that someone has a cast core roller cam or a two piece setup.

Does it make a difference in camshaft material whether the cam is for use with solid lifters or hydraulic? ALSO, what about the shavings from wear on the soft oil pump drive gear?

Most roller cams are made from billet steel which isn't compatible with a standard oil pump/dist drive. Mine doesn't have a fuel pump lobe either which I wasn't too thrilled about. I understand there's some wear of the bronze gear mostly during break in.

The billet steel of the roller cam and the steel drive gear will cold weld (transfer material) so they must be dissimilar metals. most cams are cast

I run a Crane "Retro-fit Roller" cam in my 360 and they took the billet steel cam and pressed on a cast oil pump drive gear to the shaft so I can use a standard oil pump drive shaft/gear setup. Works great! I believe they make some for big blocks as well.

Didn't CRANE go out of business? If so, I guess I'll have to check elsewhere. Thanks guys1