Brian he is not going to be able to rotate that crank 360 with the cam inactive. We almost have to assume he is still somewhere close with the crank and cam timing even though he dropped the chain or engine will have jammed up before rotating far. He would not have been able to complete rolling in the chain.
He could only be really far out on the injection pump timing in my opinion. No more than a tooth or more on the cam is possible if a 617 and still have engine rotation. He says he tried to start it remember. If the starter is rolling the engine through okay back to the injection pump. Just my opinions and subject to all kinds of things. Just do a conventional drip test before anything if the top dead centre mark and the cam mark as Brian mentioned line up. Do not line up the botttom top dead centre mark with the cam mark pointing down or cam lobes pointing down when you turn the engine prior to a drip test.