Frame/Running Gear Swap-Outs for Willys Wagons
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Considerations: Because there are so many possibilities to chose from should you want to swap-out that tired, or largely missing, Willys running gear for something more substantial / modern, certainly the first thing you need to consider is: How am I going to use my new super Wagon? Rock climbing, or backing over the neighbors petunias on the way to work? Highway or hunting? etc. etc. Be honest with yourself.

Once you've done this, then we can start to talk donor vehicles. When selecting a donor vehicle, a good place to start is by looking at width, since it can be very expensive to alter axle & housing length. The first thing that you need to know here is the difference between "tread" and "track". They are not the same. I've used "tread" on all of the specs below, but be aware of this difference when using other data.

A good rule of thumb to remember is that tread is roughly one stock wheel width wider than track, assuming that the wheels don't have a huge offset:

The distance between the two front or two rear wheels.
Front track is the distance between the center of the left front wheel and the center of the right front wheel when the vehicle is set to its normal ride height and wheel alignment specifications. Rear track is the distance between the center of the left rear wheel and the center of the right rear wheel. They are not always the same.

The following is largely gleaned by comparing the Standard Catalog of 4x4s, 1945-2000 with Illustrated Buyer's Guide. Jeep, and trying to figure out which mistakes were whose. Please email any corrections, or further info to Here's a question right off the bat: in what axle positions were the various Wagoneer front & rear differentials?

Willys Station Wagon / Panel Delivery (Note: the following dimensions apply to all years of Willys Wagons / Panel Deliveries)

Specs are located on the Basic Wagon Data page.

Chevrolet Blazer / GMC Jimmy (Note: Jimmys' specs are virtually identical to Blazers)
This is a very popular conversion, and adds some needed track width for off-road stability. Older Blazers are cheap and plentiful. Blazers built from 1969-72 have wheel base is identical to the Willys Wagon, while later models through 1991 have a wheel base that is only 2.5" longer. The advantage of the later Blazers is that you can place those front forward of the Willys stock location, thereby gaining added fender clearance for those 35+" tires that you're probably going to use. Also note that the later models' tread is a little wider.

Wheelbase: 104"
Tread: front 64", rear 61"
Wheelbase: 106.5"
Tread: front 65.75", rear 62.75"
Wheelbase: 106.5
Tread: front 66.7", rear 63.7
Wheelbase: 106.5
Tread: front 66.1", rear 63.0"
Wheelbase: 111.5"
Tead: front 64.1, rear 63.5
1995-99 (Blazer name changed to Tahoe)
Wheelbase: 2 door 111.5, 4 door 117.5
Tread: 2 door front 63.6, rear 63.6; 4 door front 64.1, rear 63.5
At a later date I'll add a year-to-year look at equipment specs for Blazers.

Jeep Wagoneer, full size Cherokee
Another popular conversion that makes sense for all around use. Wagoneers have a reputation for guzzling fuel, but their running gear is beefy. Replacement and aftermarket parts are not as plentiful as for Chevys. When you shorten the frame, consider giving yourself a little extra length to get large tire clearance on the front fender wells. Technically, Wagoneers advanced tremendously over the years. So, if you purchase a Wagoneer, you ought to get a later model one - you should be able to find one dirt cheap.

Wheelbase: 110"
Tread: front 57", rear 57"
Note: an independent front suspension was offered from 1963-65. Very rare.
Axles: front Dana 27AF (27IFS for independent), drum brakes; rear Dana 44, drum;
Automatic Transmissions: 3 speed Borg Warner AS-8W to '65; 3 speed GM Turbo Hydra-Matic TH-400 intro'd in '65
3 Speed Manual transmissions: T-90A, '63-'65 (OHC 6 cyl); T-85 '63-'67 (V8); T-14A '65-'70 (6 cyl); T-15A '68-'70 (V8)
4 Speed Manual Transmission: T-18 '68-'70
Transfer Cases:2 speed Spicer 20 single speed 21 on '63 to '65 w/ BW auto
Kaiser produced

Wheelbase: 110"
Tread: front 57-57.3", rear 57-57.5"
Axles: front Dana 44 drum brakes (front Dana 27AF 1971-72? Dana 30 in 1973?), rear Dana 44, drum
Automatic Transmission: 3 speed GM TH-400
3 Speed Manual Transmissions: T-14A (6 cyl); T-15A (V8)
4 Speed Manual Transmission: T-18A
Transfer Cases: 2 speed Spicer 20 (manual trans); 1 or 2 speed BW 1339 (Quadra Trac full-time 4wd)
American Motors produced
1974-1979 Wagoneer & Cherokee

Wheelbase: 109"
Tread, front: standard track 58.8-59.9"
Tread, front: wide track Cherokee Chief: 65.4-65.5"
Tread: rear: standard track 57.5-58.5"
Tread, rear: wide track Cherokee Chief: 62.3"
Axles: front Dana 44 open knuckle, disk brakes; rear Dana 44, drum '74-'75; rear AMC 20 '75-'85
Automatic Transmission: 3 speed GM TH-400
3 Speed Manual Transmissions: T-14A (6 cyl); T-15A (V-8)
4 Speed manual Transmission: T-18
Transfer Cases: 2 speed Spicer 20 (manual trans); 1 or 2 speed (?) BW 1339 (Quadra Trac)
Misc: six stud wheels replace 5 stud; stronger frame w/boxed rails, 1976; term "Sport Utility" first used by Jeep in 1974; wide track Cherokee Chief intro'd 1976
American Motors produced
1980-1985 (Grand) Wagoneer and Cherokee

Wheelbase: 108.7"
Tread: similar to 1974-79 models
Axles: front dana 44 open knuckle, disk, rear AMC-20, drum; Tremec Automatic Transmission: Chrysler 727 Torque Flite
3 Speed Manual: None
4 Speed Manual: Tremec T-176
5 Speed Manual: Warner T-5 (only in '82?)
Transfer Cases: 2 speed NP-208 w/ Command Trac (standard trans, part time 4wd); 2 speed NP-229 w/ Selec Trac (part time 4wd w/auto) '83-'86; 2 speed NP-219 w/ Quadra Trac
Misc: 1981: drag free rotors intro'd; improved A-727 converter; 1983: last year for SJ (full size) Cherokees 1984: Wagoneer becomes Grand Wagoneer with intro of smaller Wagoneer and Cherokee
American Motors produced
1986-1991 Grand Wagoneer

Wheelbase: 108.7"
Tread: front 57-58", rear 57-58"
Axles: disconnect-style Dana 44 front, disc brakes; Dana 44 rear, drum; Automatic Transmission: 3 speed Chrysler 727 Torque Flite
3 Speed Manual Transmission: none
4 Speed Manual Transmission: Tremec T-176 in '86, then none
Transfer Cases:2 speed NP-208 w/ Command Trac; 2 speed NP-229 w/ Selec Trac, 1986 only; 2 speed NP-242 w/ Selec Trac, '87-'91; 2-speed NP-228 w/ Quadra Trac
Chrysler produced after early 1987; 1991 "Final Editions" becoming collectible

230 c.i. overhead cam 6, 1963-mid 65
232 c.i. inline 6, mid 1965-early 71
258 c.i. inline 6,early 1970-86

Note: only the 258 was available in California, 1981-83

AMC 327 c.i. V8, 1965-mid 68
Buick 350 c.i. V8, mid 1968-early 71, also used in 1971 1414XL Special
AMC 304 c.i. V8, early 1971-72
AMC 360 c.i. V8, early 1971-91
AMC 401 c.i. V8, 1974-78

Jeep Cherokee / Grand Cherokee
I've never seen this done, but it may be a sleeper conversion for somebody that wants an economical daily driver. Cherokees are unibody construction, but they do have a lightweight frame integral with the floor pan. If you have a Wagon with a rotten floor pan, you might consider grafting the Wagon body to a Cherokee floor pan. I haven't done the engineering work on this, so I don't know if it's possible. Older Cherokees (look for one with a factory towing package, because it should have a Dana 44 rear end) are pretty darn cheap.....
Dodge Durango / Dakota
Early Ford Bronco
International Scout