suggested t case mods?

Hi all - great site and lots of info for my ongoing build.
I have a 90 XJ limited with 3.5" home brew lift (bronco coils/dakota leafs) and RS5000 shox. Also I put turbo new yorker hood vents in. Other than that she is pretty much stock. Here's where it gets good.....

I have a rusty's 6.5" longarm setup to go in with 3" blocks for the rear (temp until I figure out exactly what I want to do for the rear)
I have an 8.8 explorer rear end (still needs to be converted to discs)
I have the RE SYE for the np 242 t case
I have a welder and tools for making my own bumpers, roof rack, etc...
I have 4 - 31" MTR's on alum AR rims with a backspacing that puts them out further. (came as a package deal - used but in very good shape)
I also have 4 black steel AR rims for future tires - maybe 33"?35"?

Right now I have an opportunity to buy an AW4 tranny (for spare) and another NP242 tcase as well as a front driveshaft (to be used in the making of my custom hybrid rear explorer/front xj driveshaft)

My plan is to take this NP242 and put the SYE on it while on the bench, then just swap that one into the xj when the rear end, shox, brakelines, etc are all ready for the 6.5" lift.

My question: is there anything else that I should consider doing to the tcase while I have it on the bench? How feasible is it to swap in some gears from another tcase for lower crawl range without affecting highway gears?

thanks in advance for any info.

i don't know about the 242, but you can take what i know about the 231 and re-search it for the 242.

tera2low kit for rear wheel low only.

upgrade the planetary gear from 3gear to 6gear.

wider/heavy duty chain.

that's all i know off, and all i would invest money in since you can get those cheap/free.

otherwise, see if you can find a 4-1 out of a TJ rubicon and swap it in.