GM 10.5/11.5, 38Spline, 4340 (34.8" ->38.8" ) Full Float AXLE (8x3.563" ). Yukon 4340 Chrome Moly rear axle for GM 10.5" 14 bolt truck and 11.5", 38 spline. This is a cut to fit axle which fits 34.8" to 38.8" applications. Yukon 4340 Chrome Moly alloy axles offer a strength increase over stock while retaining a low cost. Yukon 4340 Chrome Moly alloy rear axles come with a limited lifetime warranty against manufacturing defects. The factory spindles will need to be machined in order to accept these axles. Please verify bolt pattern on 2011 & later models. This axle has a 3.562" bolt pattern. Some late model applcaitons use a larger bolt pattern.