OK - Time for new plugs, points, condensor, rotor and cap. All good except for the plugs. My old ACDelco 45's are no longer available - only ACDelco R-45's. My original manual says to use non resistor plugs. What would be the difference? I have no radio in the truck. Do resistor plugs offer a suppressed spark? Can't find anything in the search archives to answer this. BW