RockTrix - 4pc 1.5" Thick 8x170 Wheel Spacers with 14x1.5 Studs (Fine Threads) for 2003-2018 Ford F-250 F250 Super Duty, 1999-2019 F-350 F350 Super Duty (Single Rear Wheel Only) [FORD APPLICATIONS] 2003-2018 F250 & F250 Super Duty (Non Harley Edition). 1999-2019 F350 & F350 Super Duty (Single Rear Wheel Only). See Description to see Important Notes. [IMPORTANT FITMENT INFORMATION] 1) Measure wheel gap for clearance. You will need at least 1.5" (38mm) of fender clearance to prevent the wheel/tire from hitting the fenderliner. 2) Measure your vehicle's wheel studs. It must be less than 1.5" (38mm). 3) Check the thread size of your vehicle's wheel studs. It must be 14x1.5. [SPECIFICATIONS] Set of 4. 1.5" (38mm) Thickness | 8x170 Bolt Pattern | 125mm Hub Bore | 14x1.5 Threaded Studs/Nuts [MANUFACTURING] CNC Machined to exact specifications from Aerospace Billet Aluminum. Undergoes anodizing process to prevent corrision. Includes pre-installed heat treated 10.9 grade studs. [PRODUCT BENEFITS] Gives your vehicle a more aggressive stance. Improves handling characteristics and stability. Fixes brake caliper clearance issues. Increases tire clearance to allow installation of wider wheels and tires.