Sorry I wasn't more specific. This is the inner end of the axle where the tripod, or trunnion, fits, the inner CV joint. The two axles have different diameters as well as spline count. I don't have the exact measurements at hand but it is about 2-3 mm difference. Maybe my quest should be for the correct inner CV joint, or if possible, just a different tripod, if the CV pot is the same. It seems impossible to source inner CVs alone. The entire axle assembly is usually the only choice.