That really sounds like it jumped time because of a sloppy timing chain.
It is also possible that the balancer ring has moved, but usually when the timing mark jumps around it's the timing chain.
You can get it close if the balancer has moved by getting the number one cylinder to TDC and making a new zero mark, then set the timing again using the new marks.
If I remember right, every quarter inch on the balancer is 5 degrees.
