Axle Under Truck Arm? & 5Lug>6Lug?

[ProjectDD]

I've done some googling, which mostly entails this site as search results. I'm curious, could you mount the axle below the truck arm? Obviously the mount needs swapped to the top side of the tube. Also, can I convert the 12bolt rear to 6 lug by swapping axles and brakes? I have to ID my rear as to whether it's an early or later year housing for width. I'm not against get axles made for the width I need. I just don't see the need to swap to a larger rear end when my current one is posi.

I'm looking at potentially converting my 2wd to 4wd. Wondering if I could run a truck arm setup in the rear vs making a 4 link. Thinking swapping the axle to below would give me a lift or get me to 4x4 height. Also looking at Dana 44s for the front and most are 6 or 8 lug. So hence the, convert the rear 12bolt to 6 lug.

Thanks for any insight