This listing is for a Set of (8) MAHLE Original Pistons compatible replacements for 2008-2010 Ford 6.4L Powerstroke Diesel F250 F350 F450 F550 Pistons & Pins with Rings in STANDARD Size.The Bore size will be 3.866" diameter. These apply to VIN "R" 32-V Engines. VIN Refers to the 8th digit in the vehicles ID number in lower Driver side dash. NOTE: Ordering this item will require a signature confirmation upon delivery. Please ship to an address where a signature can be obtained from UPS.