Well, not really. Technically they never went away, but the company did see some downward spirals for quite some time. Not anymore though, as National Spring has been recently bought by a family that knows the leaf-spring industry well and is ramping up to bring the National Spring name back to its full glory. And they certainly proved it to us by producing this impressive 10-leaf prerunner pack that would not only lift the rear of our truck, but also dramatically improve the ride quality. National can build all sorts of leaf springs, but since this truck was never going to be hauling more than a couple of jet skis or a motorcycle, we could have some long-travel units built without overload leaves for a smooth ride.
When installing leaf springs, it's easiest to do one side at a time. We unbolted the U-bolts, threw out our temporary blocks, and removed our stock leaf springs, one at a time. We like to jack up the side we are working on, throw jackstands under the framerail (in front of and behind the leaf-spring perches), and let the axle hang from the leaf spring. Using a jack under the axle, we can now easily remove the U-bolts and drop the axle or raise it back up. The new National Spring leaves bolted directly in place of the factory springs. This is easier said than done since we had to drop the gas tank to get the front driver-side spring-perch bolt out of the frame. Remember to order new U-bolts when getting your new leaf springs!
We love this truck! The solid-axle swap portion of this project really could be done in a weekend, in time to drive (in 2WD) to work on Monday. The front flexes really well and is surprisingly stable, even without a sway bar. For SoCal freeway speeds and high winds, reattaching the sway bar would not be a bad idea, though it would most likely inhibit off-road twist. The rear National leaves complemented the front end extremely well and smoothed out the bumps that used to throw the back of the truck around. As far as power goes, the truck can squeal the tires at a stoplight with the 4.88 Yukon gears and 37-inch Baja MTZs.
With the fiberglass fenders, we were able to squeeze on the 37-inch tires without any fender interference, plus give the truck some unique styling to boot.
The pushbutton 4WD shifter works just fine with the solid axle as well, though the "Auto 4WD" is now useless and the little light will now blink when in 4-Hi or 4-Lo (because it is not getting a sensor reading from the front actuator, which was deleted with the IFS).
Also, the ABS and brake lights are now permanently on when we drive the truck. We also have no ABS, something that we are pretty happy about considering how many times ABS has tried to kill us off-road when the rear end started to slide. And with the big Dana 60 brakes in front, our braking ability feels like it has actually been improved over stock.