This is a somewhat odd situation, as the codes that come up would not be for a 5 lug axle. The codes you provide from the axle tube break down like this; HA= '67-'69 1/2 ton w/3.73 ratio, 3= month built (May), 16= Date built, W= Warren assembly plant. It could be possible that the shafts have been swapped for 5 lug.
