I wiped a *&^@$%#*^ lobe off my cam,

71Duster said
On the oil side I have been buying the addatives and I e-mailed Royal Purple out of curiosity when thinking about the switch now that the engine is broke in.

The rep told me I didn't need any additive for a flat tappet cam and it would be all good.

Any opinions?

From everything I've read/heard about zinc/phosphorous additives I personally would not take the word of your rep as gospel. For the minimal expense I would use the additives if I were you. I prefer to learn from the mistakes of others than to make them myself.