Put a good set of silicon plug wires on to rule out your ignition wires leaking,do not run any wires under the distributor,you can also plumb in a 4 lbs n/o oil pressure switch into oil pressure gallery and tie it in series to the distributor wiring so that there is no ignition until oil pressure is achieved ,once the engine is spinning ,oil switch closes and ignition is applied.If you do both of those things it should correct the fault.
Cheers