Product Details: Builder axle inner knuckle "C" Required to be welded to the axle tubes ~3.500" ID ~1.875" bore length (inboard face to counterbore face) Counterbore is ~.125" deep and ~3.975" diameter Ball joint style Allows 1550 series u-joints to fit Fits 2005+ Ford F-250 and F-350 outer knuckles or Reid knuckles for the same application These do NOT include the upper ball joint caster / camber bushing (Spicer 2008860) Uses Spicer 708238 ball joints (2) required per front axle Requires clearancing to run aftermarket non-Spicer brand 1550 series inner axle shafts (clearance the C and/or the shaft face) Parts Included: (1) inner knuckle "C" Fits: 2007 - 2018 Jeep JK and JKU Wrangler with the Ultimate Dana 60 front axle 1999 - 2004 Ford Dana 60 F-250 and F-350 front axle housings with 3.5" OD tubes for custom applications (use 2005+ Ford F-250 or F-350 outer knuckles or compatible Reid knuckles) Other applications with custom machining and fitting Brand: Dana Spicer Part Number: Dana Spicer 2023561 Warranty: 6 month warranty and case by case basis.