Well..... I'll tell you what I did to mine, but then I use mine for business.
1) Since truck came minus engine and trany I put on a 351 V6 (yes V6 not
V8!) with a NP 540 (I think?) 5 speed. Converted to 24V of course.
2) Replaced ring & pinions with 4.10, this requires a different dif carrier
in the rear however and after doing it I decided that 4.56 would have
been just fine. Also installed detroit locker.
3) Moved rear drive shaft from stock location to other flange. This
eliminated ALL transfer case noise and heat. Check with a drive shaft
shop that handles Spicer, the flange(s) you need are in there somewhere,
it's been so long I don't remember which ones.
Now I can criuse at 70 mph and get 11 mpg with ample power to tow and no
noise, it's great !!!
Currently converting it to propane with an 80 gallon tank, don't ask why and
I won't bore you with the details.
je