If your breaking in your truck this is normal... Sometimes you get lucky and your plugs wont go out so quick, but usually when your running your engine rich on fuel like your suppose to when breaking it in. Your plugs go out quickly. You might run 3 of 4 tanks and then BAM you need a new plug. Once its all broken in and you get your tuning just right, your plugs will last a long time. ALSO, have you looked at your plugs? are they black? Brittle? Broken off?? But if you are breaking in your truck dont get worried this is normal.