To make up for the 3.73 gears in my new 86 axles (85's had 3.90's) I installed a 1983 SJ-410 tcase. An 84 would have been almost bolt in but I couldn't find one. It has 1.590 reduction in high range

The 83 forced me to swap the parking drum from my 85 to match bolt patterns, and I had to get 2 driveshaft flanges from SJ's to put on my front driveshaft and the little one from the tranny. The u-joints are the same size, just use the internal SJ clips.

I used a Canadian Tire U-joint on one, and a NAPA joint on the other. From what I can tell the NAPA joint is of inferior quality, it's internal snaprings are too thick to fit in the grooves of the shaft, and it is not greasable.

I did the 4-low conversion too, the details are on off-road.com's zuk pages