Flat fender tub on CJ frame

Discussion in 'Flat Fender Tech' started by popeye, Feb 27, 2012.

  1. Sep 10, 2012
    82cj7401

    82cj7401 Member

    Orange Va
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    I just picked up a 75 CJ5 frame, axles and steering, no engine, or trans. going to swap in a Buick 225, SM420 and a dana 20 or 300. most likely the 20 as I already have it.
    I would like some of the do's and dont's if you do not mind.
    Thank you.
     
  2. Sep 10, 2012
    wheelie

    wheelie beeg dummy Sponsor

    York, PA
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    You probably already know this but, the '75 frame will yield a slightly longer wheelbase than an early frame. It may throw the "look" off a bit more, in that the front axle will be even more forward of where it would be with an early frame. If you align the rear wheels with the rear wheel well opening, when using an early frame, the front axle ends up about an inch or 1 1/2" forward vs. the original flattie frame. Using the same process, with an intermediate frame, the front axle would be several inches forward. The wheel bases escape me at the moment but, I think you'll be maybe 4" forward. May look funny in the front fender area, if it matters to you.
     
  3. Sep 10, 2012
    nickmil

    nickmil Super Moderator Staff Member Sponsor

    Happy Valley, OR
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    '72-'75 CJ-5 wheel base is either 84" or 84 1/2". Early CJ-5 is 81". Flatfender I want to say is 80". The rear of the frame and rear springs will hang past the rear of the tub and front axle will be pushed way forward. It's do-able but be aware of this. The wheelbase differences are why most people use early CJ frames or DJ frames.


    Sent from my iPhone using Tapatalk
     
  4. Sep 10, 2012
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    The 72-on wheelbase is 3" longer (84" v. 81"), but the front clip is 5" longer. So, to have the grille up by the front cross-member where it would be in the CJ-5, you'd have to lengthen the flatty front clip by 5".
     
  5. Sep 11, 2012
    82cj7401

    82cj7401 Member

    Orange Va
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    Forgot about the length in the front as well. Probably go back to using the 56 DJ I have and swapping in the 75 stuff.
    Maybe by the time I get to this project I might run across an early CJ5 set up with the 225 already in - for cheap.

    Dsylexia is great, you get to relearn stuff you already know!

    Anyone ever cut the center out of the 5 frame to shorten it to 80" at a quick glance it looks like it might be doable.


    Thanks
     
    Last edited: Sep 11, 2012
  6. Sep 11, 2012
    Warloch

    Warloch Did you say Flattie??? Staff Member Sponsor

    Falcon, CO
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    The way I do the Flatty on an early 5 frame, you really have to know what to look for to see it. I have the '49 on the '62 frame and drive train now and driving it in the yard.
     
  7. Sep 11, 2012
    WRMorrison

    WRMorrison Member

    Mesa, AZ
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    For those of you who have done this, do you normally title the vehicle with the CJ2A title/VIN or the CJ5? I've been mulling over a project like this lately...

    -WRM
     
  8. Sep 11, 2012
    82cj7401

    82cj7401 Member

    Orange Va
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    Can I cut the 75 frame and shorten it in the middle to get the 80"
    I still have tht 56 DJ frame and maybe a line on a late 60's frame with orig. V6 mounts.

    friend says, throw it on the 75 frame, weld a bumper on the rear, throw the body on, weld in the 225 engine mounts, put a winch and a stinger on the front and wheel the hell out of her. enjoy the extra length when it gets tough.
     
    Last edited: Sep 11, 2012
  9. Sep 12, 2012
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    To me, the appeal of the 55-71 CJ-5 frame under the flatty body is that it looks like a flatty. Per the CJ-3B board article, you can either shorten the rear frame horns, or let the extra length stick out at the back and hide it with a bumper. If you use the '75 frame and flatty body unchanged, it will obviously be a hack job. If that's ok with you, then go to it. But a good flatty body seems like something I would not want to waste on an abomination. JMO.

    If you want to cut the frame, I suspect the right place to cut is ahead of the cowl, in the same region where the extra body length is. Could be complicated ... the front of the frame is boxed on these Jeeps, and you'd have to change the spring mount locations. This will likely change the spring/axle geometry - I think the frame has some rise/drop in this area.

    What's wrong with the DJ frame? If you can cut the '75 frame, you can build the DJ frame into anything you want.
     
  10. Sep 12, 2012
    Warloch

    Warloch Did you say Flattie??? Staff Member Sponsor

    Falcon, CO
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    I have always titled mine with the flatty VIN. All of the 5 stuff I have used have been from parted vehicles.
     
  11. Sep 12, 2012
    nickmil

    nickmil Super Moderator Staff Member Sponsor

    Happy Valley, OR
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    Check your local laws. Some states are very specific that the VIN tag and title go with the frame....
     
  12. Oct 1, 2012
    82cj7401

    82cj7401 Member

    Orange Va
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    Dec 28, 2009
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    Any difference between the 2A frame and a DJ frame? My DJ frame is fine except I would need to weld in saggy steering and v6 mounts. I have a chance at a early v6 cj5 frame for $100. seems that might be the easiest.
     
  13. Oct 1, 2012
    jasonjp62

    jasonjp62 Member

    Pennsboro WV.
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    What year DJ frame? my 76 postal Jeep the frame was close to an early 5 frame, you could put and early tub on my postal frame.
     
  14. Oct 5, 2012
    82cj7401

    82cj7401 Member

    Orange Va
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    Dec 28, 2009
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    DJ frame is a 56.
     

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