In the March issue, we followed along as the crew at Early Classic Enterprises converted the front of its new Project Suburban from a 3/4-ton work wagon to a 1/2-ton cruizer. The company's new conversion drop spindles and brake components were easy to install, and simplified what used to be a complicated process.
With the front complete, we will now turn our attention to the rear suspension. The Early Classic rear air suspension kit is a complete system and includes KYB shocks, shock mount relocator brackets, 'bags, a compressor, lines, and the company's Super Track Bar kit.
Since the Early Classic air suspension kit is designed to run approximately 5-6 inches lower than stock, the factory Panhard bar would offset the rear axle to the left by close to 1 inch. The company solves this problem with its Super Track Bar kit, which runs from the original left-hand mount over to a new bracket fixed between the rear axle saddle and the right-hand trailing arm. This lowers the mounting point to correct the angle issues, and the bar is adjustable in length to center the axle between the framerails.
The airbags have a 6,000-pound capacity per pair, so not only can you adjust your ride height, you can also tow virtually anything you desire. Early Classic's VP and general manager, Stan Hammond, did the honors of installing the kit.
1. The Early Classic rear...
1. The Early Classic rear air suspension kit is as complete as they come, from the shock relocators right down to the air fittings. The kit will lower your truck 6 inches more than stock, but still give you a nice ride; plus, you wont have to worry about bottoming out every time you hook up a trailer, thanks to the adjustability of the 'bags.
2. With the Suburban on the...
2. With the Suburban on the lift and the behemoth eight-lug wheels removed, the shocks and U-bolts are the first parts to come off. The Early Classic lowering kit comes with all new shock mounts and hardware, so all of these old components will be replaced.
3a. The '72-and-earlier models...
3a. The '72-and-earlier models with rear coil spring suspension use a lateral Panhard bar that locates the rear axle between the framerails; this will also be replaced with a new ECE adjustable model. The rear brake hose and parking brake cables are disconnected to allow the rearend to be removed as a complete unit.
3b.
4. The rear coil springs mount...
4. The rear coil springs mount between the trailing arm and the bottom of the frame, and are held in place with a simple spring cup on both ends.
5. The ECE rear airbag assemblies...
5. The ECE rear airbag assemblies mount to the frame using the original upper spring holes, but the diameter needs to be enlarged to 3/4 inch for the airbag's top mounting stem to fit through. Caution: Always check to be certain that any wiring, brake, or fuel lines are not in the way before drilling into the frame.
6. Early Classic designed...
6. Early Classic designed an upper and lower rear shock mount bracket set that corrects the shock angle back to factory specifications. The original upper mounts need to be removed; they are riveted on from the factory, so you will need a chisel or a grinder to get them off.
7. The new mounts bolted back...
7. The new mounts bolted back into the same holes, so don't use a torch to cut off the old ones because it might mess up the holes. The new lower mounts will go back on the bottom of the trailing arm later in the install.
8. A five-lug rearend from...
8. A five-lug rearend from a '72 C10 was located and prepped before installing back into the Suburban. A 3:73 gear ratio was selected to match the future overdrive transmission and 30-inch-tall rear Toyo tires.
9. Additionally, since the...
9. Additionally, since the plan is to haul and tow once the Sub is in service, an ECE big rear brake kit was chosen to improve the stopping capability.
10. The Super Track Bar kit...
10. The Super Track Bar kit runs from the original left-hand mount over to a new bracket captured between the rear axle saddle and the right-hand trailing arm.
11. A spacer plate is used...
11. A spacer plate is used on the driver's side to compensate for the mounting bracket on the right.
12. The new lower shock mount...
12. The new lower shock mount simply slides onto each U-bolt on the underside of the trailing arm, replacing the factory part. The upper and lower shock mount kit correct the shocks back to the factory angle to eliminate the bouncy ride you get when lowering one of these trucks.
13. The U-bolts are tightened...
13. The U-bolts are tightened to the proper torque specifications.
14. The new 'bag assemblies...
14. The new 'bag assemblies are slipped into place and tightened down.
15. The kit comes with all...
15. The kit comes with all of the needed hardware, including longer lower bolts that pass through the trailing arm and into each 'bag assembly.
16. The kit includes new rear...
16. The kit includes new rear shocks that are not only shorter, but also properly valved. Stan cannot stress enough how important it is to have the right shock for each lowered application.
17. Reinstalling the driveshaft...
17. Reinstalling the driveshaft revealed another problem, due to the fact that the original C20 rearend yoke uses a larger U-joint cap compared with the new C10. This dilemma is easily solved with a crossover U-joint available at your local auto parts store.
18. With all the suspension...
18. With all the suspension components installed in place, the air fittings are screwed into the top of each airbag. The supplied air hose is carefully routed between each 'bag, then forward on the framerail to meet the compressor and storage tank.
19. The tank and compressor...
19. The tank and compressor can be mounted in any number of locations, and the crew at ECE likes to hide them under the hood next to the radiator. This keeps them out of the weather, and the fan and engine noise tend to mask the compressor when it's running.
20. The pressure gauge and...
20. The pressure gauge and switch are mounted on the same panel, and can be located anywhere on the dash. Because the Sub' will basically run at one height, Stan chose to hide the panel inside the glove compartment. This makes for a clean installation, and keeps his young son, Tyler, from constantly hitting the switches.
21. What a difference a lowered...
21. What a difference a lowered stance and new wheel and tire combo make. The Centerline Sundance-series Dagger wheels and monster Toyo Proxes are what made the difference. Stan chose 18x8-inch front wheels with 255/55R18 Toyos and 20x10-inch wheels with 295/45R20s in back. This combination stuffs the Sub's large wheelwells and gives it a fantastic stance.