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Transmission/Transfer case question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 74Jimmy, Mar 2, 2002.

  1. 74Jimmy

    74Jimmy Registered Member

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    I have a 1974 Gmc Jimmy that I have Had for about a year. I have finally gotten around (ie money) to replacing the engine/trans/transfer case and this is where my question is. The Truck has a turbo 350/203 with part time and 1978 blazer axles, I would like to upgrade the trans to a 700r4. What year trans should I look for? It would have to be a non-computer model which I think is 1982 but are there other years I can use? If I do switch to a 700r4 I would like to change the t-case as well what model is suggested I know a 205 is supposed to be the strongest will it bolt to a 700? Any help you guys can provide is appreciated
     
  2. Hossbaby50

    Hossbaby50 3/4 ton status

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    If you want a 700R-4 get one from an 89 or later. They are noncomputer controlled, but have all the factory updates that made the early 700R-4's burn up. Get yourself a big external tranny cooler, and a shift kit in the 700R-4 and it will be alot happier. As for tcase. I think the only tcases that bolt to a 700R-4 is the NP208, and NP241. They are both pretty good cases if you don't run alot of HP or big tires. They are not as strong as your 203, or a 205, but they will take some abuse. My NP208 has 150K on it with a fair amount of offroad miles. The NP208 has a 2.61:1 low range, where a 203, or 205 only has a 2:1.

    My Chevy isn't broken, its just out of gas. <a target="_blank" href=http://coloradok5.com/gallery/albuo73>My K5</a>
     
  3. NewK5Guy

    NewK5Guy 1/2 ton status

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    A rebuilt 700 from a reputable shop will also do. A good shop, like the one that rebuilt my 84 700r4, will do the necessary updates during the rebuild. If you plan on towing, tell the builder beforehand so they can add the necessary heavy duty parts. I did and I'm glad I did. I second that suggestion about the tranny cooler. My tranny builder was quick to recommend that after the rebuild to help extend the life of the unit. As for the t-case, run any t-case you want. Advance Adapters has the adapter you need to get any t-case to any tranny. As for t-case choice, you're on your own. The 205 is the strongest, but only has a low range of 1.96:1 where the 208 is 2.61:1. Depends on how you plan on driving it.
     
  4. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    All 700R4's were computer controlled for lock up converter. There is a kit you can buy that will allow you to do the swap and not have the computer. Painless wiring makes one for it. The 203 t/case is 2.01:1, the 205 t/case is 1.96:1, the 208 t/case is 2.62:1, the 241 t/case is 2.72:1. The 203 t/case were all fixed yoke, the 205's were both fixed yoke and slip yoke, the 208's were all slip yoke in chevy applications, the 241's were all slip yoke as well, but you can buy a SYE kit for a 241 and not for a 208.

    1989 blazer, 383 stroker, D44 / 14FF, 4.56, locked, 35 BFG mud
    Scott
     
  5. 4GUNZ4X4Z

    4GUNZ4X4Z 1/2 ton status

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    You can bolt any tcase you want to the 700. Advance adaptors has an adaptor for around $200(guess)to bolt on the 205, but if you already have the 203 and want the 205 I'd run both of them behind the 700. Remember you are going to need to do some work on driveshafts to fit properly with the 700/205
    Thats what I'm working on 700/203/205.



    <font color=blue>Professional <font color=red>JEEP EATER</font color=red> it's a population control thing.</font color=blue>
     
  6. Hossbaby50

    Hossbaby50 3/4 ton status

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    Are you sure that ALL 700R-4's were computer controlled. 4L60E's were computer controlled. Thats what the E stands for if I'm not mistaken. E= electronic. From my understanding a 4L60E is an electronically controlled 700R-4.

    My Chevy isn't broken, its just out of gas. <a target="_blank" href=http://coloradok5.com/gallery/albuo73>My K5</a>
     
  7. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    I am absolutely positive that all 700R4's were computer controlled. They changed the name of the 700R4 in 1991 to 4L60E. Prior to 1991 the computer controlled only the converter lock up. 1991 when they changed the name to 4L60E they were full electronic shifting done by the computer as well as converter lock up, hence the "E".

    1989 blazer, 383 stroker, D44 / 14FF, 4.56, locked, 35 BFG mud
    Scott
     
  8. fortcollinsram

    fortcollinsram 1/2 ton status

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    THe TH 700R-4 is a Hydraulically Controled transmisison (Hence the TH=Turbo Hydo)with and ELECTRONIC LOCK-UP...The 700r4 will be much easier to install as far a wiring is concerned than its later computer-controlled counterpart, the 4L60-E. A 205 t-case WILL bot up to a 700r4 with either a new out put shaft or a spacer from advance adapters ($180 and $400 respectively) The new output shaft requires a complete tranny tear-down to install...Unless you are gonna crawl around on rocks all day, I'd say stay with a 208 t-case...

    Was that a speed bump? No, just a Rice Rocket </font color=red> <a target="_blank" href=http://coloradok5.com/gallery/fortcollinsram>My 87 Blazer</a>
     
  9. pcorssmit

    pcorssmit 1/2 ton status

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    <blockquote><font class="small">In reply to:</font><hr>

    I am absolutely positive that all 700R4's were computer controlled.

    <hr></blockquote>

    I am positive that you are wrong, my '83 Diesel w/700 had a non-computer controlled lockup.

    Pete
     
  10. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    While we're picking on Scott...<blockquote><font class="small">In reply to:</font><hr>

    the 208 t/case is 2.62:1,

    <hr></blockquote>
    It's actually 2.61:1 /forums/images/icons/smile.gif

    Rene
     
  11. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    they are not computer controlled. they are electronit controlled. sounds the same but different. the electronis lock up the convertor. computer controlled tells when to shift and lock convertor.
    grant
     
  12. arveetek

    arveetek 1/2 ton status

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    I installed a 1990 model 700R4 in my '81 C-20. It is non-computerized. It requires only one wire to operate the lock-up function of the TC. One 12 volt wire makes it electrically operated.

    Casey
     

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