When I did my SOA on my 79, it didn't cost much (of course, I do have an auto-hobby shop and that greatly reduces costs). I ground and knocked off the perches and had to grind a perch into the diff-case but that's it... Can't remember if I used the original u-bolts or not (I've spares all over the place). True there is a lot of stuff you CAN do while you're under there (twisting the knuckles is a good idea), but you don't absolutely have too. Though, you may want to keep in mind that, at the time, I found the front driveshaft was frozen and didn't want to move at all and before I got THAT fixed, I had already found 3/4-ton axles to put underneath it (never installed them, found the 14 bolt and the 60 Front two days later)... then upgraded to the current 1-ton axles. Was a bit of work but seemed to come out alright in the end.
My Scout is like my website, I'm working on it. 79 IH ScoutII, Anything else is just a 4X4... 345, 1-ton axles, Detroits F/R. 99 F-350 SD, PowerStroke.