Severe Miss

The ol'Dart died at a stoplight. Towed it home, reduced the problem to the timing chain (Cam gear was history!). replaced the set and the plugs, everything went together nicely, fired right up. Now has a MAJOR miss. Got fire to all the plugs. Removed the wires one by one while the engine running and can't narrow it down. Any help before just go with a replacement engine. This one is at 145k. thxs