HEI coil arching

[paul67]

75 350 Corvette miss fire ,lift hood could hear and see blue flash at coil,after 5 min running,changed cap, rotor ,modul ,same fault modul died,replaced with new dissy fault still there checked wires, plug leads ,fitted new grounds ,starts first time this is happening when it's hot.Chasing this for 3 days head hurts