4WD conversion questions

I'm getting started on a 2 to 4wd conversion on my wifes 99. I have access to a cheap 89 for parts. I know not all of them will work, like the trans, and the spline count on the xfer is the 21 not 23.

I am making an assumption that I can swap my 2wd knuckles onto the 89 4wd axle to reuse my new discs and calipers as long as I use the correct newer unit bearings. Anyone able to confirm this?

I plan to get a 99 4wd aw4 later, but I am thinking of getting the 242, linkage and front driveshaft off the 89. I plan on rebuilding the 242 anyway so I can swap in the appropriate 23 spline input gear, but what would I have to do with the speedo drive?

I can get the linkage/shifter from the 89 then deal with the wiring up the lights later.

Anyone see any problems I havn't noticed?

I will instal the axle on its own first. Then do the rest at a later date.

Thanks all.

Well since no one answered I will post what I have found for anyone with a similar question.

Turns out the donor I found is a 90. The front knuckles became one piece that year so I did not need to swap them. They are identical to the knuckles on our 99 (composite rotor version of that year) 2WD so I think they could be swapped in if neccessary. The brakes on this donor were pretty new so I have spare discs, calipers, rotors and knuckles. So I simply put new bushings in the housing, replaced one bad u-joint and a wheel stud, and installed the whole thing. The gear ratio is the same. I kept my steering components, track bar, rotors and calipers. The unit bearings on the 30 were usealbe. So far I am into the conversion for about 140. I will need to find the linkage from another xj since this one was already missing.

I'm hoping my luck holds and the 242 tcase is 23 spline. I have read somewhere that the 90 was the first year, but others say 91. Should know this weekend. Plan on using a pair of front drivelines and a SYE. If i understand what I have found by searching, the linkage can come from any 4WD XJ but the metal "gate" above the the cup inside needs to be for the 242.

May not get a window of opportunity to do the trans and tcase for several months, but it's a start.