78-84 FL Shovel, 78-84 FX Shovel, 85-94 FX Model, 91-98 Dyna, 84-99 Softail, 85-98 Touring
Note: Except E78 models
Spark Plugs including a wider-base insulator which provides an easier path to speed the transfer of heat and a longer insulator nose containing a center electrode of pure copper inside of chrome-nickel to transfer heat between firings and help resist fouling.