Sorry it took so long to respond. What year is your 472? Earlier years with small chamber heads, valves could hit the piston if the chain broke or jumped teeth. Don't remember for sure what year they went to large chamber it was 73 or 74..
Does the engine turn over when you turn the key? If so, did you hear a bang? If not, remove all plugs, pull off the valve covers and see if all rockers are going up and down when turning the key. If all of that is good check the timing mark at TDC to see if both valves on # 1 are closed.
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