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4L80E to a NP203

Discussion in 'The Garage' started by kgblazerfive, May 2, 2007.

  1. kgblazerfive

    kgblazerfive keymaster Premium Member GMOTM Winner

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    Can you put a 4L80E in front of a NP203?
     
  2. Jimbo*

    Jimbo* 1/2 ton status

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    I don't know why not--MuddyBuddy's doing it. Just need to machine the TH400/NP203 adapter to fit the 4L80E, and find the correct output shaft for the tranny.
    Jimbo
     
  3. b454rat

    b454rat 1/2 ton status Premium Member

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    Yep, think you need a 400/203 adaptor, then needs to be milled to match the '80e style adaptor. But not 100% positive.
     
  4. muddybuddy

    muddybuddy 3/4 ton status

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    yep im going to be doing it in about 3weeks :) ive got all the parts (well ive got some of them paid for, just need to go get them). jimbo* machined the 400/203 adapter for me, so everything should go in smoothly. im going to bolt the 203 up to the 4L80E this weekend or so to make sure everything is gravy, so ill snap some pics for you.
     
  5. kgblazerfive

    kgblazerfive keymaster Premium Member GMOTM Winner

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    So is the 400 the same as the th350 and 700r4 what about splines on the out-put the 4l80e out-put looks rather big
     
  6. kgblazerfive

    kgblazerfive keymaster Premium Member GMOTM Winner

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    Took my wifes Sub in to get the 4l80e fixed said it was going to be 5900.00 after they took it apart told them they were high on crack and so I think they gave me a screwed t-case.
     
  7. muddybuddy

    muddybuddy 3/4 ton status

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    4L80E is 32spline (same as th400) so ull need a 203 that was from behind a th400 or swap in 32spline input out of a 27spline 203
     
  8. kgblazerfive

    kgblazerfive keymaster Premium Member GMOTM Winner

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    I wonder what spline mine is probally the 27 cause it is behind a 700r4 witha short shaft in it.
     
  9. muddybuddy

    muddybuddy 3/4 ton status

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    yep urs will be 27spline
     
  10. kgblazerfive

    kgblazerfive keymaster Premium Member GMOTM Winner

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    :D So know anybody who has a input for a 203, got a input from a 700r4 203 to get rid of:D
     
  11. b454rat

    b454rat 1/2 ton status Premium Member

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    I just gota 400/203 combo from a local guy, he said he has another one....
     
  12. u2slow

    u2slow 1/2 ton status

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    4L80Es have a longer stickout than the TH400s from 203 applications.

    I suggest using the stock 4L80E/NP241 adapter, and redrill the face of the 203.
     
  13. kgblazerfive

    kgblazerfive keymaster Premium Member GMOTM Winner

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    The adapter is not yet a problem its the input to the trans first my be selling the 98 now anyway not sure I want to make all the mods when my 87 is half the work
     

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