I have been "rehabilitating" this 81 GS450, and i noticed that the spark plug caps are in bad shape. I can't seem to find the spec for them anywhere. are they resistor type? does anyone know what level of resistance? they seem to be common in 1/5/10 ohm levels. any help would be appreciated, as a google search just brought up nonsense and generic ends. I plan on getting NGK, but not sure which ones are proper.