May try the JK ring and pinion swap. I was told by Jantz that using his setup along with good Ujoints and comp cut axle shafts the D44 will take being locked with 37s-40s with a V8. If its true or not I cant say. Still loads cheaper than a D60. Well almost. I would like to run ARBs.
I'd take the Jantz stuff with a couple grains of salt. I think the JK gears are fine but don't buy to much into it. Like the comp cut axles, it's not really a thing. I'd axles turned they way they were supposed to be. I've had/made axles like that since 2001. Brad has done similar stuff with gear further back then that.
It's a improvement but does it have to be done? Hard to tell. Better then a D60? Sorta and not really.
Stulc has D44 with Chromoly shafts from Branik I think and run 37 stickies with water. They have held up amazingly well really but they are getting stressed now and it's time for a D60.
For 35's I don't think I'd mess with the bigger gears, get some decent shafts, save the money towards something else.