Allowable slack in timing chain?

Normally you would rotate engine clockwise until you are at TDC on timing indicator, then rotate engine counterclockwise slowly while carefully watching distributor rotor. Stop rotation as soon as you see the slightest movement of rotor. Read how many degrees crankshaft has turned on timing tab. The less the better obviously. 10 degrees on a stock engine would be on the outer limit of acceptable, I would think.
10 degrees would run pretty badly.... if the chain was still on there! IIRC, one tooth off is right at 15 degrees.