Thanks mate, appreciate the help. The Cam in that thread is a roller. Mine is non roller
As indicated I'm used to using cast gear on a cast Cam, but the manufacturer doesn't make one and says the hardened steel one is OK.
Crow cams suggested melonised but didn't say I couldn't use the one supplied.
Pertronix only supply bronze or hardened steel. Nothing in between and have a different diameter shaft to nearly everyone else so its not as easy as just buying an alternate. Pertronix have sold thousands of these, so they are probably ok to use. I guess I'm just being overly cautious.