Yukon lists this short crush sleeve for 1963–1965 12-tooth or Corvette applications with a coarse spline and an approximate length of 0.630 inches. It is supplied as a replacement sleeve for the early 1960s GM Corvette and 12-bolt truck axle types to re-establish correct pinion geometry during differential assembly and servicing.
Yukon Gear 63-65 12T or 63-65 Corvette Crush Sleeve / Short / (Coarse Spline)