Pull all the plugs to unload compression. Remove the distributor and inspect the distributor gear for cut out teeth. Inspect the cam gear teeth with a light down the distributor hole while some one turns over the motor or turn it by hand.
Hopeully the distributor gear is all that's wiped and the rest is ok. Remember that the distributor gear takes all the force of spinning the
oil pump and hi flow pumps take more power. If the chain had broken or sprocket came loose you would not have been able to turn over the motor without bending valves.
Replace the distributor gear with one that is appropriate for your type of cam (hardness of the cam teeth). Check the cam gear
teeth for wear or chips. Check the
oil pump drive rod to be sure it is not rounded off by the distributor shaft. Remove the pan and clean out any chips or dust that might damage the
oil pump. Replace the oil filter. Find the compression stroke for cyl. #1 with your finger over the spark plug hole - stop the crank at TDC on the Crank pointer - point the rotor button near the #1 plug wire post - insert the distributor and see if the rotor still points at the #1 post - if not insert the distrib. in again at a little further rotation until it is close to pointing to the proper cyl. Loosely tighten the distr. clamp until you final set the timing while running.
Watch the oil pressure like a hawk for a while.
Good luck,
tm