Dana 44 HD, does it exist formally?

[justcuz]

Hey everyone, I need a little help. I am having a discussion over on Pirate 4x4and we are having a disagreement about the existance of a Dana 44 HD front axle.
Ford had 2 different front axles in their F-250 4x4's in the bumpside trucks
(67-72). Both were Dana 44's but one had the bigger balls and knuckles and external 6 bolt hub flanges with the big spicer hubs like Chevys. The other was an internal hub design like a half ton with the smaller ball and knuckle (half ton size). The Ford owners manuals for 1969 and 1972 refer to a Dana 44HD but no Dana /Spicer axle info shows this designation that I can find. Also in 1976 when Ford finally put disc brakes on the F-250 they still had the external flange Dana 44 HD but it went to an open knuckle like Chevy had since 1970.
Chevys as I recall, even back into the 60's used the external flange 6 lug hub on their 3/4 ton 4x4 trucks. The early ones had the aluminum hubs with the small center dial and the later ones had the big spicer hubs with the plastic center dial. I don't think Chevy ever used the lighter duty front axle in their 3/4 ton trucks. Dodge either as I recall except Dodges all used Warn hubs to the best of my recollection.
My question is this, does anyone have access to a Dana/Spicer 44 front axle information that specifically designates the difference between a standard Dana 44 front axle and a Dana 44 HD, or did Ford do this in their owners manuals to designate the difference between the two axles?
I think the Ford HD axle in closed knuckle form used Dana 60 balls and knuckles, but as far as I can tell the axles, housings and gears were all the same. I know the Chevys had thicker tubes as probably did the Ford and Dodges. In open knuckle form they had the bigger external hubs and thicker tubes, but not much else.
Anybody out there able to shed any light on this?
P.S. This question does not include 10 bolt 3/4 ton front ends that did use the internal hub front knuckles starting in 1977.