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Swapping in a 700 to replace a 350C

Discussion in 'Transmission & Transfer Case' started by Matt69olds, May 7, 2019.

  1. Matt69olds

    Matt69olds Full Access Member

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    ok square body gurus, once again I come to dip my cup into the well of knowledge! I would like to replace a tired 350C trans with a fresh 700 with lots of durability upgrades. My question, what’s needed to complete the swap? I have already replace the steering column with a later part, that will fix the shifter gate issue. The 350 trans has a long output shaft, anybody in readerland know if the driveshaft will fit? If not, I’m guessing driveshafts are pretty easy to find. I have a PRNDL indicator with the overdrive position, and have already addressed the lockup converter wiring, and modified the Q-Jet with throttle arms to accept the TV cable. I’m guessing the existing crosssmember can be reused? Anything I have overlooked? Thanks!!
     
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  2. yevgenievich

    yevgenievich Full Access Member

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    Driveshaft fits, crossmember slides back and bolts back in. Might have to drill new holes in the frame for it. I found the 700r4 and th350 cross members being actually different but either still fits if holes are made for it. Sounds like everything else you already have. My column on 85 truck was either wore or already had the right gate as just swapping the indicator was enough when I did the swap.
     
    Last edited: May 7, 2019
    MrMarty51 likes this.
  3. 84 M1008

    84 M1008 Supporting Member Supporting Member

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    Be sure to add an oil cooler preferably mounted in from of the radiator. Derale offers a few fan driven coolers of different sizes. Heat is the death of a 700R4 and will burn one up quickly. The aux cooler is pretty much a must.
     
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  4. Matt69olds

    Matt69olds Full Access Member

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    Forgot to mention the trans cooler, truck already has a temp gauge.
     
  5. Battlac40

    Battlac40 Full Access Member

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    I'm guessing you have a 208; make sure the spline count is the same.
     
  6. 4WDKC

    4WDKC Full Access Member

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    He said it has the long tailshaft... doesnt that indicate it is 2wd? If not front driveshaft will need to be longer, rear shaft shortened and t case linkages will need to be modified,
     
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  7. Matt69olds

    Matt69olds Full Access Member

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    I guess I should have mentioned this is a 2wd truck.
     

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