How much slack should the timing chain have?
 

While making a failed attempt at adjusting the valves, I noticed that the timing chain isn't super tight. It has probably a 1/2 inch of play when I put tension on it. Is that too much?

When I put my chain on it had about the same amount of slack. So I'm gonna say it should be fine.

There should be NONE, ZERO, NADA, NO slack. When you re-install the timing chain, you are supposed to push the chain guides in while tightening. I actually use big wood clamps to keep them all the way in while I tighten them down.

lol I honestly never did that. When I set the chain and tensioner on I had about the same slack and I just took the timing cover off today and the slack is gone. I never messed with the guides either

the tensioner kicked in once you started it. tightened it up.

Interesting, I just pulled my valve cover off today and noticed the slack in the chain. Figured I would just replace it considering the current predicament my car is in...

No slack indeed, the chain tensioner can pick up but if the chain is blocked when the cam wheel is taken off getting it back on should be a tight maneuver

Since the tensioner is only spring loaded, it will allow the chain to slacken when the engine is turned backwards a couple of degrees.....which happens about 50% of the time during shutdown.

On cars with high mileage, you can hear the chain hit something as it goes backwards from compression while you bump the engine to adjust the valves.

timing chain
 

one side of the timing chain should be tight like your 1st girlfriend and the other side has the same tension onless you manually turned the crankshaft the wrong way while adjusting valves