700R4 question

Discussion in 'The "Juice Box"' started by gscalifornia, Mar 26, 2020.

  1. Bens99gtp

    Bens99gtp Well-Known Member

    What size tire are you running. Figure out what rpm you want to be running at what mph and see what's needed to make that happen

    Weigh out the pro and cons

    700 requires an adapter which will require a converter to be spaced to take the thickness up
    Drive shaft mod
    Cross member moved
    But will gain alot more 1st acceralation due to gearing.....but will have a huge spread between 1st and 2nd

    200 no adapter
    Might not need driveshaft or crossmember mods
    Slightly steeper 1st gear but not a huge spread

    I did a chevy car for a customer 383 about 425-450 hp. 3.73 gears.....his tires were about 28ish tall if I remember correctly

    We did a 700r4 that had a circuit inside the trans to lock the converter up.....no external source, it was a monster trans.....everything worked very well....cable was touchy to get adjusted but they always are on both 700 and 200....we had about 3000 flash stall........at 65 it was like 2100 rpm........had tons of first gear........but the spread made 2nd feel slight soft if you were not in it hard.....
  2. Fox's Den

    Fox's Den 22 years of racing the same 355 Buick motor

    The 200r4 trans is a bolt right in and with a 410 gear and 28" tire it will be a terror. The problem with adding the adapter to make the 700 work is just one more thing that has to be tightened up and one more place for things to move.

    There are many places that can build a 200 trans very nice piece. I use a switch to lockup the convertor and I can lock it up in 3rd gear when just cruising at 40 mph when 4th gear is not needed.

    I lost a little time on the 60 ft at the track but was all made up by the 1/8 mile but I went from a 3500 stall in the 350 turbo trans to the 3000 stall with the 2004r trans.

    Definitely went faster on nitrous with the 200 trans.
    Real world
  3. gscalifornia

    gscalifornia Small blocks rule!!

    Found a 200R4 core from a 88 Cadillac Brougham and am wondering if it would be a decent starting point? Guy said car had a knock and changing transmission fixed it, he thought it may have been a bad converter.
    TexasT likes this.
  4. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    Yes that’s a good core, just have it freshened up and new converter.
    gscalifornia likes this.
  5. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    I suggest a new Tv cable.

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