I had already attached the brake mounting flange to the axle via the U-403 axle flange as well as trimmed & demurred the wheel pant mounts and fabricated the associated spacers. With all that done, the first one went together really easily. No problems at all.

However, the starboard side was a little bit of a struggle. When I installed the caliper on the slide pins, it was tight. I could push it back and forth, but there was quite a bit of resistance. clearly something wasn't right. Long story short, I took it all apart and discovered that the ears on the U-403 were slightly warped, probably during welding. It was just a few thousandths, but it was enough that when you torqued the associated brake flange down, it put the pins in a bind.

Took that all apart and encouraged the ears on U-403 to get with the program via an aluminum drift and BFH while is was sitting in my bench vice. Only took a few taps to get it in good shape.

WARNING- It turns out it's possible to put this assembly together wrong and have everything still fit. When I put this back together on the bench, I got the brake mounting flange behind (ship side) the U-403 axle flange when it should have been outboard. I bolted everything up this way including calipers and it wasn't until I started looking at it in place that something didn't seem right. Referenced the other side and immediately saw what I'd done. I believe the down side of doing it that way wouldn't have been catastrophic failure, but instead, the caliper "float" would have been limited much more than by design and eventually things would have bound up or just stopped grabbing as the pads wore down.

Took it all back apart and re-assembled it the correct order/stackup. All good.

Drilled axles for cotter pin with a 90* drill motor first to #40, then took the nut off and upsized to #30

Few other things of note;

The two AN4 bolts that hold the pads on are now safetied with Nordlock washers, not safety wire. The instructions say 1/4" nordlock bolts get torqued to 100 in/lbs. That seems awfully high, so I called Matco and they verified.

Vans instructions tell you that you'll need to swap the bleeder fitting the other way on one of the calipers to make a left and right. On the ones I got, that had already been done out of the box.

Nordlocks get higher than standard torque

The wheels that come in vans finish kit now have a rubber chevron style integral grease seal and it takes a different tightening process that we're all used to. Basically, as spelled out in the installation instructions you rotate the wheel while tightening the nut until the seal stops spinning and then tighten it to the next locking feature. Since you're drilling the axle to match the holes already in the axle nut, you're basically left to you're own devices to figure out where this is.

From the point the seal stopped spinning, I went approx. 1 more flat and then drilled the holes so taht he pin would be vertical.