71 Dodge Dart Swinger in England

Check shaft to housing side to side play, and shim the air gap with .006" brass or stainless shim stock. I cant remember what the ohm value of the magnetic pick up coil is to test w a meter but i am sure you find that on the net. If its "no bueno", rock auto has these made by standard for pretty cheap, along with a new reluctor if needed. I wonder if its maybe the ignition module or ignition coil giving you a fit.