the procedure was to have the WD system lower the whole vehicle evenly, front and back (equal squat
I don't know the origin of this idea but it is completely wrong. Trucks are made to carry the load on the rear axle. There fore the SQUAT will not drop equally as you apply a load. The rear springs are designed to take the load while retaining close to original fender height. The front springs are designed to remain in as close to original height as possible in order to retain the steering geometry. If you were to drop the axles equally under load you would drastically change to front end alignment and wear the tires. This factor is less important with front leaf springs but very important with A frame front ends.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles