Jeep AJ-8 Build Up - How Rick Russell Built His Sidekick Off-Road Rig:

Once the decision has been made on how you'll use your 4x4 and a body style has been selected, you're ready to make the second most important decision in any buildup project, "What size of tire are you going to run?"

Whether you're building a 4x4 from scratch or upgrading the one you have, you'll need a plan. There is always some fine-tuning to do after it hits the dirt, but if you don't have a plan you may find yourself spending money reworking the vehicle instead of fine-tuning it.
The first and most important decision to make on any build-up project is deciding, "How you intend to use your rig?" Is it a trail or street vehicle? Regardless of your choice there will be trade-offs. How much street ability are you willing to give up to make a better trail rig? How much off-road capability are you willing to compromise for more comfort and stability on the highway? Is your 4x4 a daily driver? Will you whimper over body damage? Are you going to trailer it or drive it to the trailhead? Is someone else going to drive it? That can be very important. In my case, I want a "dual sport" model: a street

The dash is a combination of Autometer Gauges and K-Four sealed switches. This cool electronic speedometer can be reset for any changes in tire size or gear ratios that might be changed in the future. The custom dash was easily wired into the Painless Wiring Harness.

and trail rig. And I am willing to sacrifice some highway performance for better off-road performance.
Today there are enough aftermarket companies making 4x4 accessories and replacement parts that we have a choice for most items. Whether you're looking for nerf bars or a suspension system, in most cases there are several styles and manufacturers to choose from. In fact, there are so many aftermarket parts available for Jeeps that a complete Jeep can be built without ever buying one. And that is exactly what we did. 
This project 4x4 will not be a daily driver. On the other hand, I want to be able to drive it 1,000 miles on pavement to reach a trailhead, lower the air pressure, run a trail like the Rubicon Trail in California or Pritchett Canyon Trail in Moab, air-up the tires and drive home. Both of those trails can push a trail vehicle and its driver to the limit.

Originally the AJ-8 was built with a Warn 9500ti, which worked great. It was upgraded to the new Warn Powerplant. This resolved the problem of where to mount a high volume air pump without sacrificing winching capability.

Another consideration is air conditioning. Do you need it? I do. From my home in Southern California, no matter which direction I drive, I will pass through the desert. That means summer temperatures above 100 degrees. So not only does this street and trail rig need enough room to carry people, camping gear and food for at least 4 days, but it also needs air conditioning for those hot days and a heater for cold, winter trips.
Deciding how a 4x4 will be  used could influence the choice of a body styles and personal preference plays an even larger roll. For this project, a bobbed CJ-8 aluminum body (Scrambler) from Aqualu Aluminum Bodies (from Canada) was selected because the wheelbase is similar to my 1956 CJ-6, but with the larger, late model door openings. More importantly,

It took about three months to collect all the parts for the AJ-8. It was assembled in just 36 hours, but it took another 3 months to fine tune the AJ-8.

aftermarket hard doors are available for this body style. The wheelbase of a CJ-8 is 103" or about 10" more than a CJ-7 or Wrangler. The slightly longer wheelbase of the CJ-6 and CJ-8 provide a smoother ride on the highway and has more room. The frame was built by Jeremy Pulse of TDK in Moore, Montana (formerly with AFW). Their frames are mandrel-bent making them both smooth and strong. Our frame was ordered with the Jeep TJ suspension brackets already welded in place. This provided us with several standard suspension upgrade options. Since this build-up Jeep is being assembled from all aftermarket parts, it was dubbed an AJ-8 (Aftermarket Jeep) where the "8" identifies its origin in the Scrambler body style.

At the heart of the AJ-8 is a Ramjet 350 crate motor from GM Performance. With 400 ft lbs of torque and 355 hp produces plenty of power, it's sold complete with wiring harness and computer. It was perfect for our "Street & Trail" project.

Once the decision has been made on how you'll use your 4x4 and a body style has been selected, you're ready to make the second most important decision in any buildup project, "What size of tire are you going to run?" The tire size will determine the strength of the differentials you'll need, how much lift will be required, the gear ratios, the size of the motor, the optimum transmission and transfer case to use. Obviously the motor, transmission, transfer case and gear ratio must all work together. So deciding on a tire size will narrow down the choices of drive train components.
A tall tire will provide better ground clearance off-road, but can create steering issues on the highway. Like most Street & Trail rigs, the AJ-8 will spend a fair amount of time on the highway. After much thought I chose 37-inch tires and a flat belly pan to give the vehicle a slight advantage over those 4x4s equipped with 33 or 35-inch tires but still be manageable

A GM 700 R4 automatic transmission using a truck torque converter and transfer case adapter from Advance Adapters connected the Ramjet 350 motor to an Atlas II transfer case built with the 3.8 low range ratio.

at highway speeds. This size tire required trimming the body around the rear tires, trimming the front fenders, adding a 1.25" body lift and installing a standard 5-6" suspension lift. I actually have two sets of tires and wheels. One is 37x12.5x17 Goodyear MT/R on Walker Evans beadlock wheels; and the other  is Pro Comp 37x13.50x17 Xterrain tires on a set of custom beadlock wheels. The MT/R tires work good on the trail and highway, and the Pro Comp's soft surface performance of the Xterrain is hard to match. Why beadlocks? Not only does the tire stay on a beadlock wheel at low air pressure, but also the beadlock ring protects the aluminum wheel from rock damage. When the ring begins to show wear it can be replaced without buying a complete new rim. There is a disadvantage. Beadlocks require that you regularly re-torque the ring bolts. I think you'll agree that how you are going to use your 4x4 and what size of tire you're planning to run, will guide any 4x4 project build-up.