Thought I had a good combo but now Im not sure!!

mmjhull said
Was your heads also open chamber iron heads?

Yes 2.02 J heads 66CC smoothed combustion chamber, Fel Pro 1007 head gasket, sharp edges removed from valve reliefs, 180* thermostat, Autolite 65 Copper core plugs, old analog MSD 6AL, 24 initial/35 mechanical total.