[Tom Wells]

on the material the camshaft itself is made of.

Most of the roller cams are steel, so a steel or aluminum-bronze distributor gear must be used.

A "normal" cam, usually cast iron, uses a cast iron distributor gear.

If you use the wrong mixture of gear/cam materials you will get the result you experienced. For example, a cast iron distributor gear used with a steel cam spells disaster.

My 514 crate motor came with a steel roller cam and a steel gear on the end of the distributor.

Hope this helps.

Tom