New timing chain, allowable slack?

I just got off the phone with a tech @ Cloyes, and with the way I described the fit I have now he suggested trying one of their stock size hand-matched billet units, as he thought the deflection I'm seeing in the chain wasn't excessive. If that's still too loose he said I could return it for an undersize one, and at least I'd be using one of their sets to check with. Apples to apples for comparison/measurement, not trying to figure a fit based on a different manufacturer's set.