Started my D22 project a few weeks ago. The fuel pump failed a few months prior, so I pulled the bed, replaced the pump, and got to work. I pulled everything off the frame except the tank, all of which got disassembled (even the leaf springs), cleaned up with a wire cup, painted, and reassembled.
The rear axle conversion is nearly complete at this point.
At this point, the main stuff that's left to do is finish up the parking brakes, shorten the driveshaft, and install the catback exhaust.
As far as the disc brake swap goes, this time around the dust shields on the backing plates were in a good-enough condition to keep. The calipers needed a lot of work...the pistons were toasted by the previous owner (one of them had become molten at one point), so everything got rebuilt.
I ran into a snag a few weeks ago when I realized I nearly all the parking brake hardware was missing. For reference, this is a complete assembly.
The good news is that a 300ZX disc brake hardware kit (Carlson 17418) is nearly identical, and included almost everything. RockAuto didn't show any kits for a WD21, and this kit doesn't crossref either, but after a few OE part number lookups, I was able to confirm all the main parts (in particular the spreaders) and a few springs were the same or similar enough to chance.
Left missing was the bigger metal piece near the top that separates the shoes (called a "strut") for both RH and LH sides, and one of those triangular-ish washers. The washer was also used on 300ZX, but dealers want $55(!) for it, and the struts are NLA...and were only used on WD21s. I was able to find a parts broker who can get 2 of the washers for $1/ea and a RH strut for a few bucks, but not the LH. Better that nothing, but there'd still be a problem if I couldn't find another. Of course, I could just use the truck without a parking brake (which is, unfortunately, typical of many homebrew swaps I've seen...no thanks.)
Yesterday I went to a several JYs hoping to find another WD21, but no luck. At my last yard, I came across a 94 Honda Passport with disc brakes and figured that since it was another Japanese 6x5.5-bolt 100mm-bore setup from around the same time, maybe it'd be similar. The rotor's drum shape/size looked questionable, but I pulled it anyway. The internals looked very similar, but I couldn't confirm any dimensions at the yard, so I pulled the washers and struts and took a chance. Sure enough, they were practically identical...in fact, the washers were identical.
The struts weren't an exact fit, but they were super close.
The length was nearly spot on, maybe 1-2mm shorter between the throats than the OE piece (not entirely sure because I didn't pull apart my truck to find out), but the only fitment issue was that the throat on the lever side was just a little too narrow.
A few seconds with a flat file, and they fit perfectly now.
So anyway, if you're missing hardware, a hardware kit for a 300ZX, and bits from a Honda Passport/Isuzu Rodeo (and several other related applications) will do. It may also be the case that a similar parking brake hardware kit for those trucks works, too...looks very similar. (On a related note, parts from the vehicles have been used on D21/D22 2WD disc brake swaps for a few years.)
With all that sorted out, I'm stoked I can move forward with the parking brakes. I'm taking a different approach to the cables than I did on the R50, and I think it'll turn out a lot better. The general idea is to splice the mounting foot from the WD21 cable onto the D22 cable.
I've cut up a WD21 cable enough to get all the insulating boots/shields off it, leaving the foot that's crimped to the cable jacket. I'll cut the jacket a few inches down from the crimp, and then do a similar cut on the D22 cable (the cable needs to be extended a little during this process anyway). They'll be crimped back together with a 2/0 compression butt splice connector, then resheathed. Should look pretty stock when it's done. More to follow...