agree… the best option in this case is to recheck/redoo … replace all the suspect electrical components if any doubt exist on the quality of wires, boots, coil connections etc… at least it would eliminate that part of the puzzle (fuel oxygen…. fire)
the arrival problem coincides with the new cyl head presumably it was resurfaced and installed properly so the external variable here are the wires or plugs . (unless Murphy showed up in the meantime)
a bad plug interchange could move the problem over to the top cyl … end of problem 🙂
the next step is a close look over of the lower cyl HV circuit all the way back to the coil HV pin
jmho
Joining AOMCI has priviledges 🙂
