In order to use the D44 knuckles on the D35 beams, you need to ream out the lower ball joint taper.
Here is the reamer sitting in the D44 beam, taped up to mark the depth:
here it is in the d35 beam:
The upper ball joints are the same in the beams. They both accept a caster adjustment bushing that is the same outside diameter.
The dana35 adjuster is on the left. The dana44 bushing on the right is tapered on the inside, while the dana35 is straight cut.
I got the taper cut for the PS beam, but the DS wouldn't cut all the way. The damn reamer is dull already. New one will be here Saturday.
In the meantime, I got Pigeonrat up on the lift.

That's a lot of stuff to remove.
I did some looking to see what my track width is going to look like.
The original 1991 Nissan Pathfinder chassis I have has a front track width of 56.1".
I got the D35 out of a Bronco II with a track width of 56.9"
the D44 came out of a 1993 bronco so has a track width of 65.1"
Using the D35 and 2" spacers (to convert to 6 lug), I'll be gaining about 5" of track width. If I'd have gone with the d44 it'd be 11" with the spacers. I'm not ready to go that much for now. Of course, as mentioned above, I think I could use chevy hubs and avoid using the spacers to keep it at 9", but I'm going to stick with the d35... for now.