First, there is a split for Dana 44 3/4 ton hubs. You'll want the 77.5-79 style, as it is more common and runs the same lock out as the 1/2 tons.
The other style is for disk brakes is 76-77.5, it uses a much larger hub and lockout. Pic
Second knuckle, here is a pic for you. From my Dana 44 flat top article. This shows where the 1/2 ton is notched for the caliper.
Spindels, I've seen people post different stories. Dana book for a 1978 shows a 1/2 ton using 706110x for an inner wheel bearing, a 77.5-79 using a 706074x and a 76 using 706139x. They all have the same outer bearing. One thing, you can't go wrong getting the proper 3/4 ton spindle.
The other style is for disk brakes is 76-77.5, it uses a much larger hub and lockout. Pic

Second knuckle, here is a pic for you. From my Dana 44 flat top article. This shows where the 1/2 ton is notched for the caliper.

Spindels, I've seen people post different stories. Dana book for a 1978 shows a 1/2 ton using 706110x for an inner wheel bearing, a 77.5-79 using a 706074x and a 76 using 706139x. They all have the same outer bearing. One thing, you can't go wrong getting the proper 3/4 ton spindle.