Short answer, gap your plugs @.035
The dr "8" heat range is probably where you want to be.
Long answer, the "8" and the "9" indicate the heat range of the spark plug. Ironically, the higher the number, the colder the plug. If you were running flat out, the colder plug would be acceptable, but when you have to contend with stop n go, extended idling, cold start ups, the "8" would be the one to use. Since you live farther north than most of us, stick with the "8" gapped @ .035
The dr "8" heat range is probably where you want to be.
Long answer, the "8" and the "9" indicate the heat range of the spark plug. Ironically, the higher the number, the colder the plug. If you were running flat out, the colder plug would be acceptable, but when you have to contend with stop n go, extended idling, cold start ups, the "8" would be the one to use. Since you live farther north than most of us, stick with the "8" gapped @ .035