I got the old chain routed through the crank sprocket and back up again. Equal lengths coming out on both sides.
I found a broken piece of chain rail.
It was wedged in the chain and crank sprocket, on the driver side of the engine. It's most likely part of the inner or outer slide rail. It might have actually broken off from that wedge of chain that was jamming up the injection pump gear. Definately the outer slide rail.
Another order.
I wonder how critical it is to have that top 1/2 inch of that outer sile rail?