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

I measured it (not by degrees). With a straight-edge against the sprockets I can push the middle of the chain 0.318 inches (yes - it was 318 I swear!). That's 5/16 inch (5.1 / 16 to be exact). So it's not the 1/2 inch that's supposed to be the rule of thumb for replacement.

There's a lot of things you can replace "just because you're there" that's cheap and you're reasonably sure you're not taking a step backwards (like thermostat, water pump, this or that bushing or tie rod end). I'm not convinced that a timing set is one of those, not in my case.

What's tight, for a new chain? 1/16 inch? 1/4 inch? 0/16 (barely able to put it on) ? My experience is with timing belts on the LH-era 3.5L so I don't know what to expect here. I only have read that new chains are not necessarily tight.

Since I'm in Kanada and the local prices can be krazy, I end up buying from Rockauto, and in this case I'm seeing timing sets from EnginTech, FVP, Cloyes, Melling, Ultra-power, with prices that range from $26 to $190 (that's CAD). The $190 is a Cloyes race billet undersized by .010 with 9-Keyway crank sprocket. The "heavy duty" Melling or Cloyes (double rollers) are $50.

Probably at some point I'll notice one of those on wholesaler discount and buy it next time I'm getting something from RA, but for now like I said I'm going to leave this chain on.....