The new Pro Guard D2 Performance fuel-filter kits help improve fuel filtration and flow to 2008-2010 Ford Super Duty 6.4-liter V-8s. The filters are made from NF21 synthetic materials that reduce flow restriction, utilize 99-percent filter efficiency, and weigh 2 pounds. The Pro Guard D2 fuel-filter kit includes both chassis mount and engine mount filters. $50-$62.