Current: Rear D44 out of an 87' cherokee that is 5 lug 1/2 ton. Running 37" DC mud tires on 9" lift

Planned: I am about to change the gearing to 4.88 and swap out the aussie locker for an ARB locker. At the same time I do this I would also like to upgrade the axle shafts to 4340 chromoly and change everything over to 8 lug 3/4 ton and disk brakes to match the front axle.

I know I will need to swap out the 1/2 ton spindles, hubs, rotors, bearings and races for 3/4 ton as well as the backing plate to mount the disk brakes. My question is what (year/make) spindles, hubs, calipers/rotors will I need to perform the conversion? Also I was looking at the 4340 axle shafts and they are 33 spline which is different then the original 30 spline that came stock. Are these the right shafts for my D44 and if so then I will need a 33 spline ARB to match the shafts as well correct?

33 spline shafts are aftermarket and stronger than aftermarket 30 splines, it would be a stronger (but possibly more expensive) setup than going with 30 spline things.

Why not go with a 1 ton rear axle? You won't have to mess with the bolt pattern, and you'll get a stronger axle...it will most likely be cheaper too

*EDIT* And I didn't even notice...you talking about a full float 44? With hubs and spindles you must be...and knowing that you'll be looking at new housing ends to accomodate the new spindles if I'm not mistaken.

ya i was also thinking about swapping over to a 14 bolt because its stronger and could possible be cheaper. What 14 bolt would be the easiest/cheapest to install?

all of them...

Get one from 86 and later if you can. The drums slide on instead of being bolted to the backside of the hubs, and the pinion bearing is larger and stronger.