Early CJ-5s still represent an affordable way to get into the vintage Jeep thing, with decent drivers often selling for not much more than $1,000. The '55-'65 CJ-5 and its 101-inch wheelbase sister, the CJ-6, came standard with the F-head 134, Dana 25 front and Dana 44 rear axles with 9-inch drums, a T-90 or T-98 transmission, and the Spicer 18 T-case. In 1966, the Buick 225 V-6 was available with a T-86 and later the T-14a three-speed and Spicer 18. The Dana 44 rears, in from about '70 1/2-'71, were the desirable one-piece, 30-spline shafts.
Steering gears on all CJs up through 1971 were the scary Ross cam and lever system just like the first military flatties; it wore out and gave little control. Consider upgrading to a later manual- or power-steering system. Also, the '66-'71s have better 10-inch drum brakes and a dual-piston master cylinder that stops these Jeeps pretty well. If you want military cool, look for a '52-'57 M-38A1 or the ultracool and elusive '53-'57 M-170 101-inch wheelbase ambulance.
For the '72 model year, the front of the CJ was stretched to accommodate AMC's 232 inline-six, and the 304 AMC V-8 became an available option. Transfer cases changed to a Model 20, with the Dana 30 front and excellent 30-spline Dana 44 with centered pinion bringing up the rear. Both axles had 11-inch drum brakes and a wide range of available ratios.
Other changes of the AMC-era CJs were a move to a frame-mounted manual- or power-steering box, better steering linkage, and a 2.5-inch increase in wheelbase. If you're looking for an older, vintage Jeep to wheel but don't want to deal with a lot of steering, axle, and drivetrain swaps, the '72-'75 intermediate Jeeps offer lots of solid components at bargain prices.
Oddly enough, the CJs of this era have relatively poor aftermarket support. Axle, gear, drivetrain, and mechanical parts are easily found, but little things like bumpers, seat frames, rollcages, and even suspension components are harder to come by than their later CJ and Wrangler successors.
With the longer 101-inch wheelbase (103.5 for the '72-'73 Commando), the Jeepster offers a good wheelbase and decent interior room for a trail rig when compared to a smaller CJ-5 or flattie. There's a little more breakover angle and body to contend with in the rear, but the added room may be worth it to many family wheelers.
Base engines are the 134 F-head, but you'll want to nab a Buick 225 V-6 model with either the T-14a three-speed manual or TH400 auto tranny. The only T-case available was the 2.03:1 Dana 20, with axles ranging from the closed-knuckle Dana 27 up through 1971 and the open-knuckle Dana 30 for '72-'73. The rear axle could either be the pathetic Dana 30 or the good Dana 44 with two-piece ('67-'70 1/2) or one-piece shafts ('70 1/2-'73).
Jeepsters used a lot of the same drivetrain components as the CJs, but the rear springs are Jeepster-only items, so if you're looking for an over-the-counter lift, you're not going to find it. Steering components and so on are pretty much the same as the CJs. The front sheetmetal from a CJ can be made to fit a Jeepster, but the rear tub is unique to the model. Lots of soft top and hardtop options were offered-from half cabs to fastback soft tops. There's some odd stuff out there.
For '72-'73, the Jeepster became the Commando, available with AMC's 232 I-6 or 304 V-8. They look like Scouts and are quite possibly the most hideous Jeeps ever made.
These trucks came with engines ranging from L- and F-head four-cylinders to an unimpressive flathead inline-six. None really does the trick, and that's why nearly every truck and wagon we see for sale has a swapped-in V-8 or later inline-six. The stock T-90 and Spicer 18 tranny aren't the stuff of big, heavy truck-building, so plan on swapping the rest of the drivetrain while you're at it. There's plenty of room under the floorboards to suck up a big manual and low-hanging NP205, if that's your thing. The stock Dana 25 front and Dana 44, Dana 53, or Timken 51540 rear usually meet the scrap yard in favor of newer, fullsize running gear from a Chevy, Dodge, Ford, or Jeep truck.
There are a few companies making replacement interior and trim parts, but they're getting expensive, so if aesthetics are important to you, try to buy a truck that has all the pieces in good shape. Also, check the frames around the suspension components for cracks and the framerails just in front of the rear-spring hangars. It's common for these frames to rot through in this spot.
Without listing the myriad drivetrain components these trucks came with through the years, there are certain caveats to consider when looking for your old FSJ. First, the 230ci OHV Tornado six-cylinder is a solid engine, but it doesn't like to be overrevved; rod-bearing problems result, so check the oil pressure and listen carefully before buying a stock one. The Rambler 327 doesn't share any parts with the Chevy 327 or later AMC engines, and components are expensive and usually require special order. Even the starter is over $200 from most places. The first AMC 232-equipped trucks until 1969 may or may not share the same bellhousing as later AMC 232/258/304/360/401 engines, so if you're looking for an easy engine swap, it might not be in the cards. There are a lot of automatic-equipped trucks, but if you want a T-98 or T-18, it's best to find one that came from the factory that way because the clutch pedals and linkages are starting to fetch more money.
As for the axles and suspension, all of the early trucks before 1974 have closed-knuckle, drum-brake Dana 44 fronts that will most likely need to be swapped if any real wheeling or towing is in the truck's future. Rear axles are Dana 44 or Dana 53s, but a Chevy, Dodge, or Ford 1/2-, 3/4-, or 1-ton axle fits easily. The early Wagoneers came with an even worse closed-knuckle Dana 27 front, but the Dana 44 front from an early-'70s narrow-trac Wagoneer bolts right in. Steering is provided by the very good frame-mounted manual or power-steering that is easily upgraded with modern boxes and parts. If you're working with an older truck, your choice of lift kits will be limited or nonexistent. Rear lifts on these are usually accomplished via flipping the rear shackle and using blocks on the factory springs.
Later AMC-era trucks enjoyed durable 232, 258, or AMC V-8 engines, strong trannies, good Dana 44 axles, and strong TH400 or TF727 trannies. Just steer clear of the full-time BW Quadra-Trac T-case if you don't want to get your hands dirty; most of these cases are worn and need a chain and or differential replacement.