Wake up a 1968 318...

[QUOTE="cudamark, post: I'd check the chain slop just by rocking the crank pulley back and forth to see how much play there is. [/QUOTE]

But remove the distributor cap first so you can watch the rotor.

If the crank turns without immediate rotor movement, the timing chain is worn.

Rotate the crank until the rotor moves, then rotate the crank in the opposite direction. If there is a lack of movement in the rotor, bad timing chain.