sorry, missed your question after the large photo.... not sure why the wouldnt be compatible with BJ arms. i know when i mounted a set on my 05 tacoma, i used the tacoma OEM UCA due to the fact that i ran DR at 1" lift, for a total of 5" up front.
EDIT: i know there is a slight difference between the tacoma and 4runner/FJ OD on the BJs, maybe the shaft is different enought to not be compatible? probably best to call camburg themselves.
check out the maxtrax spindles, they are half the price. I had a set of these back in the day on my 05 tacoma prerunner when i lived in socal and it was either these or the TC $1,250 ones. i agree with above, the powdercoating (at least back 7 years ago) was a lot to be desired and i remember i had to chase all 4 hub threads to ensure i could properly screw in the bolts without galling or crossthreading. i also remember there was something to do with the ABS sensor as liqourish mentioned.
remember, 4" lift spindles will only work on 2wd truck. this is due the shifting in the mounting point such that the lower ball joint mount is right in the way of the front CVs on a 4wd.