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Rim size/backspacing for 33x12.5 on 78 CJ5?

Discussion in 'CJ' started by Slim78cj5, Oct 27, 2018.

  1. Oct 27, 2018 at 4:18 AM
    #1
    Slim78cj5

    #1
    Slim78cj5 [OP] Member

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    Eric
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    I have 78 cj5 with a 2.5 in lift. Would like to put 33x12.5 on it. Going for classic look. What rim size do i use? 8 or 10's? Also what backspace is needed so they don't rub on springs? We do have a fender law in my state. Thx 4 ur time...
     
    Slim78cj5, Oct 27, 2018
    #1
  2. Oct 27, 2018 at 5:27 AM
    #2
    OFFGRID

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    OFFGRID Well-Known Member

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    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    IMO 8s will keep it under the fenders, but 10s will look better and likely stick out past the fender flare a tiny bit. With only 2.5in of lift I think i would run the 8s to keep from rubbing the fender in hard bumps. If you want another inch of height check out the bone shackles at https://www.rocky-road.com/jeep-shackles.html. Around 3.25-3.75 back space would be best.
     
    OFFGRID, Oct 27, 2018
    #2
    aggrex and Bob like this.
  3. Oct 27, 2018 at 7:30 AM
    #3
    Slim78cj5

    #3
    Slim78cj5 [OP] Member

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    Ok Offgrid, If i go out past fender a little it should be a problem an inch or so. I've been told if i use 10's tires will rub on springs when turning hard. Is this true? Should i go with a smaller tire with the 2.5 lift. I'm hesatint about death wobble also. This is my 1st Jeep project. It has been in family 31 yrs and has only 11000 miles. It was a plow jeep for our driveway its whole life now its time for a sunday driver life. Haven't put lift on yet. Just started tear down so... Thx for any wisdom u can share with me
     
    Slim78cj5, Oct 27, 2018
    #3
  4. Oct 27, 2018 at 7:31 AM
    #4
    Slim78cj5

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    Slim78cj5 [OP] Member

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    Past fender shouldn't be a problem if an inch or less
     
    Slim78cj5, Oct 27, 2018
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  5. Oct 27, 2018 at 7:42 AM
    #5
    aggrex

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    aggrex Well-Known Member

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    Tuffy>AEV>TTO>JW>STech>EVOcage>MagnaFlow>SpiderTrax>RockHard>TF>SpringTail>67design>Bolt>GPCA>Curt>
    Welcome @Slim78cj5 ...post some pics of that Sunday driver
     
    aggrex, Oct 27, 2018
    #5
  6. Oct 27, 2018 at 8:02 AM
    #6
    Slim78cj5

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    Slim78cj5 [OP] Member

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    Post will be coming soon. Just put in garage and started tear down for a winter transformation. Leaving stock 6 cyl. I'm for now but have a 304 for it. Just tryin to gather info b4 I get to far into project. How much lift can u use b4 u have too extend driveshaft brake lines and such. My 1st concern is safety because my daughter will get this jeep someday.
     
    Slim78cj5, Oct 27, 2018
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  7. Oct 27, 2018 at 1:37 PM
    #7
    aggrex

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    aggrex Well-Known Member

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    Tuffy>AEV>TTO>JW>STech>EVOcage>MagnaFlow>SpiderTrax>RockHard>TF>SpringTail>67design>Bolt>GPCA>Curt>
    @Slim78cj5 check out @daddyusmaximus CJ7 build/restoration for some ideas for your winter transformation. I don't own a CJ but something about flipping a frame upside down for restoration is intriguing.
     
    aggrex, Oct 27, 2018
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  8. Oct 27, 2018 at 7:52 PM
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    OFFGRID

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    OFFGRID Well-Known Member

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    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    I had a 2.5 in lift on my CJ7 and ran 33s on 10s and it did well until I took it offroading and hit a very hard bump and smashed my left fender when the tire compressed into it. On the street and beach and dirt rodes you'll be fine. 10s or 8s it doesn't matter about rubbing on the spring. it is the back spacing that matters. IMO the 78 cj7 with its narrow width axles needs the 15x10 wheels, but will look good with the 8s too.
     
    OFFGRID, Oct 27, 2018
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  9. Oct 28, 2018 at 10:42 AM
    #9
    Slim78cj5

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    Slim78cj5 [OP] Member

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    0k, so i go with the 10's is there a way to figure out which back space you suggested to go with? Of course I have amc 20's narrow axles. So the widest stance i can get and keep close to fender edge is the goal.Thx 4 ur patience.
     
    Slim78cj5, Oct 28, 2018
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  10. Oct 28, 2018 at 1:09 PM
    #10
    OFFGRID

    #10
    OFFGRID Well-Known Member

    Joined:
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    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    . Above I meant 3.25 inches to 3.75 inches of back space would be best. It's hard to find 3.25 inches now, but that would be best. Most are 3.75.
     
    OFFGRID, Oct 28, 2018
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