How much free play should new timing chain have?

Could be another reason for the slop if it's been line bored in the past by someone who doesn't know how to do it correctly. The correct procedure is to chuck the block up in the bore in such a way that the bar takes a very, very light skim off the main bore halves in the block and more off the main caps. Doing it in this fashion results in almost not moving the crankshaft center line in the least. Many shops will not take the time to set it up this way, so you end up with the crank center line that is raised, which results in the timing chain being loose. Of course you can get custom length chains for that, but who wants a bastard block like that when it can be avoided with good machine work?