I should add one more thing.. all 7400/7402/7403 hubshells are not identical. I was sifting through my box of Dura-Ace jetsam, and noticed that some of these shells require a donut-shaped steel washer in order to provide space between the freehub and hub shell. Similar to later Hyperglide freehubs.

The consequence of not installing the washer is that the outside of the freehub will bind against the hub shell. Again, this is only certain freehub/hub combinations.