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[noob]which 203 for 400/203/205??? [/noob]

Discussion in 'The Garage' started by KRAZIE87K5, Nov 21, 2003.

  1. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

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    Hey folks... sorry for the noob-ish question... but I'm looking for what 203 I need to locate in order to build a 400/203/205 setup. I've got the 400/205 setup complete... now I need to find the 203 and an adapter. Please clue me in. I've searched... but its a tough question to search for..

    Thx,
    -Dan
     
  2. ramjet gmc

    ramjet gmc CK5 Staff Staff Member Moderator GMOTM Winner

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    you need the 203 from the trann you want to conect to it will use all the stock add


    the only thing that is non stock is the ORD add and you will need a new brace to

    http://www.coloradok5.com/orddoubler.shtml if you havent seen it
     
  3. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    You need a 203 with a 32 spline input that came behind a Th400. This is pretty hard to find. These are on 78-79 K30s with the full time 4WD option and some rare Subs (3/4 ton) and apparently the odd K5 blazer (or so I've been told). In any case, you can buy just the input from Stephen to convert the "common as dirt" Th350 203 to 32 spline input.

    Next up is the adapter, it is unique to the Th400 203. But, the 203 range box can be redrilled to use several different adapters including the late round adapters for a 205 or 208.

    Finally, the trans output shaft must be 32 spline and the right length for the adapter your using. The shortest is the Th400/203 adapter which has a unique output shaft to match. Basically, you need the 32 spline output shaft and Th400/??? adapter to match...
     
  4. cybrfire

    cybrfire 1 ton status Vendor GMOTM Winner

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    what the other guys said but there is one more option. You can use the 400 trans with a 208 output shaft and the 305/203 adapter. Then you get a 4 bolt to 6 bolt adapter to go from the 400 trans to the 350 adapter. This takes care of the drilling hassle and the extra length of the 400/208 output shaft. I just talked with Stephen at ORD the other day and this is the route i'm gona end up going. The 400/208 out put shaft is common as dirt and so is the 350/203 adapter. Give him a shout. He said they are just about ready.
     
  5. BIGJ

    BIGJ 1/2 ton status Author

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    Dan, I've got an extra TH350 version 203 if you decide to go that route. No adapter though /forums/images/graemlins/frown.gif . PM me for more info if you're interested.

    BIGJ
     
  6. jac6695

    jac6695 1/2 ton status

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    I have the adapter and rangebox you need. I am parting out my TH400/203/gen1 Doubler/205(TH350 ver.). I can sell you the just the rangebox for $150.00 OBO plus shipping. I can't pull it out until I sell my bigblock. Thats why it isn't advertised yet. Maybe a few weeks.
     
  7. ramjet gmc

    ramjet gmc CK5 Staff Staff Member Moderator GMOTM Winner

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    [ QUOTE ]
    I have the adapter and rangebox you need. I am parting out my TH400/203/gen1 Doubler/205(TH350 ver.). I can sell you the just the rangebox for $150.00 OBO plus shipping. I can't pull it out until I sell my bigblock. Thats why it isn't advertised yet. Maybe a few weeks.

    [/ QUOTE ]

    any hint on what is on the way /forums/images/graemlins/grin.gif
     
  8. jac6695

    jac6695 1/2 ton status

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    Yup! LT1/4L60E/Gen2 Doubler clocked. /forums/images/graemlins/thumb.gif
     
  9. Mudzer

    Mudzer 1/2 ton status Author

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    Dan - pay close attention to Baddog's post - you need to make sure your TH400 you are using has the NP203 version output shaft to fit a 32 spline NP203. They are different for sure. I found this out and decided to go with TH350 - it was easier and cheaper.

    I can buy two rebuilt TH350s for the cost of one TH400 - anywhere in the US. /forums/images/graemlins/grin.gif

    Your other option is to drill and tap the face of the NP203 box using the TH400/NP205 adaptor between the two. /forums/images/graemlins/thumb.gif
     
  10. cybrfire

    cybrfire 1 ton status Vendor GMOTM Winner

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    If you decide to go with the 400/208 with adapter from ORD i got an extra output shaft for ya!

    /forums/images/graemlins/thumb.gif
     
  11. K5DRAGER

    K5DRAGER 1/2 ton status

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    I believe we have a mutual friend that should have this whole combo. Might want to give him a call. /forums/images/graemlins/thumb.gif
     

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