I recently gave my '55 Desoto a mild tuneup with a very much needed oil change and new plugs... I was told by previous owner that they came stock 6 volts, but shes been swapped 12 now. She has a stock 291 Firedome Hemi and in my shop manual for her it says the gap is .035. She running better then ever but is that too small of a gap? Thanx for any help!