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needin help

Discussion in 'Intermediate CJ-5/6/7/8' started by farmdub, Mar 19, 2008.

  1. farmdub

    farmdub New Member

    I have a72 cj5 with a 401. I have no clue what year the engine is or anythig else for that matter. Can someone point me in the right direction? how can I figure out the motor year-axle size -what tranny is it? I just tryin to sort it all out. CAN SOMEBODY HELP ME!!??
     
    farmdub, Mar 19, 2008
    #1
  2. lynn

    lynn Time machine / Early CJ5 HR Rep Staff Member

    Welcome aboard! :tea:

    Yes... we can help you with most of this.
    You'll need to post pics for us so we can give you accurate info. Without pics, we can only tell you what was stock in 1972, and guess at what you might have.

    The 1972 CJ came with a D30 front axle, D44 rear axle, and 11" drum brakes. Gears most common are 3.73... 4.27 were optional. 3-speed tranny is a T15; if you have a 4-speed let us know. Transfer case would be a Dana 20.
    A 304 V8 engine was available, and is the largest V8 ever offered from the factory in the CJs. Obviously someone swapped in the 401 you have. Look for some serial numbers on the block somewhere, and Google "AMC V8"... there are a few sites that can give you detailed info. We do have a couple members here who are 401 experts, maybe they'll chime in.

    So show us some pics of your rig; pics of the parts you have in question. Pull up a chair, grab a coffee :coffee: and tell us about this rig anda bit about yourself and your Jeep interest :)
     
    lynn, Mar 19, 2008
    #2
  3. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    No need to panic. Do you have the factory service manual? The manual for '72 is online at www.c104.net or can be purchased as a reprint several places.

    The 401 is a really easy swap for the factory-supplied 304 V8. What's your VIN number? You can confirm that the Jeep came with a 304 from your VIN.

    The 401 will have the displacement numbers cast-in to the block near the driver's side motor mount. Make sure you really have a 401. Externally, the 401 is identical to the factory supplied 304 V8; the big differences are internal. The 401 will have a 4V carb while the 304 came with a 2V; otherwise, they are the same from the outside. No need to worry about the differences between the 304 and 401 unless you need to take it apart, or need to work on the carburetor. All the other external bits will be unchanged.

    Welcome from Boston :coffee:
     
    timgr, Mar 19, 2008
    #3
  4. garbageman

    garbageman Member

    The 401 is a lot of engine for a CJ. Post up your location and you may have several Jeep owners here close to you. I'll solve the 401 problem by giving you a 258 straight 6 to replace it with. R)

    The 401 is a very desirable engine. Still, its a lot of engine for a CJ unless you want a mud runner or racer. Since the engine has been upgraded look for tags on the differential covers on axle size and gear ratios. You may have to remove the covers to confirm this.

    :uwop:
     
    garbageman, Mar 19, 2008
    #4
  5. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Yes. Be careful or you'll break it and/or crash.
     
    timgr, Mar 19, 2008
    #5
  6. grouperboy

    grouperboy n00b

    Can't imagine what a 401 would do in my rig! 258 is plenty as it is.
     
    grouperboy, Mar 19, 2008
    #6
  7. DrDanteIII

    DrDanteIII Master Procrastinator

    Thats just something that people without V8's say. :D

    But yeah, my 304 is fairly healthy, a 401 would be frame twisting fun.
     
    DrDanteIII, Mar 19, 2008
    #7
  8. wicked4x4

    wicked4x4 HEY, watch the paint!

    right, i nearly pull wheelies with my slightly built 304, doesn't take much to torque the front left off the ground 6".

    have fun with that guy
     
    wicked4x4, Mar 19, 2008
    #8
  9. jinpdx

    jinpdx Member

    I have a 72 with a 401 also. Used to run a 304, but since I put in the 401 I cant imagine it any other way.
     
    jinpdx, Mar 20, 2008
    #9