Set the timing mark to zero degrees. Pull the distributor cap using white out mark where the rotor is and on the side of the distributor. With a wrench on the crank bolt turn the crank with somebody watching and telling you when the rotor starts to turn. Stop at this point and check where the timing mark is at. Anything over 15 to 20 degrees your timing chain is stretched.
Remember when you get to the mark go a little past and turn it back then go forward.This is before you start.