v-6 in early A-body

On my 340 I used the chain tensioner with the Cloyes double roller chain and it wears 2 little grooves in the guide until it hits the rollers. I have always wondered about that, as the tensioner was made to ride on a factory silent chain.
The factory timing chains were made by the lowest bidder with the cheapest steel. That might have something to do with it also.