3.73 with a 4.0L isn't bad with 235's or I'm sure 31's wouldn't be too bad, the '91 manual trans explorer I had I put 3.73's in, shimmed the limited slip and it went well and got right around 20mpg with 235 75 15's.
If it were me I'd probably just put in the 3.73 axle since you have it, when you are doing the spring pad flip, move the alignment pin holes forward a little which will help with your driveshaft fitment so you don't have to do anything there. Then just keep your eyes open for a 3.73 D35 to swap in, if you want to get crazy, try to find a 1356 transfer case and just use it's front driveshaft, that's what I did... most of my parts came from half off days at the junkyard... I think I got paid $50 to do a disc brake swap on my 8.8 by just buying a different axle and selling it with the drums...