What's your opinion on the slack in this 318 timing chain?

The spec distance seems to be 6.125 inches. Cloyes has race billet sets for 6.120 and 6.115. I don't need a race billet with adjustable sprocket, but I would entertain an affordable set for 6.120 just to buy and try. But who makes them? Who sells them?

Are belt kits available for the 318?
You're not going to get a custom length chain for cheap. How sure are you that you even need that?