You can have the axle flanges redrilled to the 5 lug pattern, then use drums from the later 5 lug truck. Alternatively, if you can get the rearend from the donor truck that the frontend came from, you can either use the entire rear by putting the mounts frm the original rearend on it, or you can get 5 lug axles by simply having the shafts from the donor truck cut down to match the originals, then grooved for the C lock. You will also have to use the side gears from the spider set, as the later axle is 30 spline vs the 17 spline of the '64. The parts will interchange.
