My 200-4R swap adventure (1970 Buick GS 455 TH400==>TH200-4R)

Discussion in 'The "Juice Box"' started by Cutlass, Nov 4, 2018.

  1. Cutlass

    Cutlass Platinum Level Contributor

    Hello everybody,
    many of you have noticed and already contributed to the thread I initiated recently.

    Here my intension was to have a thread to just collect data about the various swaps which already have accomplished (kind of a library).

    Since then I got thinking and concluded, that for my swap project it will be very usefull to have a thread where everyone interested can just contribute and nobody (including me) feels somewhat bound to the particular format of the thread. This is my motivation to open this particular thread. Hopefully my intension come across ok, as english is not my native tongue.

    So here we go:
    Thanks to techg8 my attention was brought to something I have not even started thinking about. Modification of my carborator. I have a 1969 Rochester Quadrajet installed. It looks like being all original and I am somewhat hesitant to weld, or even just drill a hole. Most likely the next issue will be hood clearance once the carborator is raised enough to get clearance of the TV cable to the intake manifold. I definately want to keep the stock dual intake aircleaner. What are my options in that regard?
  2. TexasT

    TexasT Texas, where are you from

    The everyday performance setup is a great way to be able to retain the carb you have. Another might be to run the cable into the gas pedal similar to how the "kickdown cable" is attached in a stock setup. Either will work. Just have to decide on the one that is best for you.
  3. Cutlass

    Cutlass Platinum Level Contributor

    Here is a picture of my carb. Where exactly would I run into clearance issue between TV-cable and intake manifold? If I would use the spacer kit from everyday performance, would I still be able to use the stock aircleaner with enough clearance to the hood? Unfortunately my car is in offsite storage for the winter so that I am not able to provide better pictures.
    IMG_3456_low.jpg motorraum_low.jpg
  4. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    How about s side view pic. Youl need to weld the square for tv cable housing under the throtle cable. You can get a threaded cable holder and drill the arm someware on the bottom half. Next you want to learn about using a pressure gague pluged into the tranny and getting the adjustment right.
  5. Cutlass

    Cutlass Platinum Level Contributor

    OK, decision about how to connect TV-cable with carb is made:
    I'll get an Edelbrook performer intake and additionally I have the electric choke, the bracket for the TV-cable and the TV-arm-conversion kit from Ken (techg8) already in transit.

    I got the first quotes on the transmission coming in. Two out of eight recommended to swap to a 700R instead of a 200-4R, guess I'll ignore those :). Two have not even bothered to answer for a week now, I'll follow up with them on the phone next week when I am in US anyway. One (Vince Janis) I had to call, because he does not have a working website and the email adress I found is no longer working. I talked to him yesterday and have a very good overall impression about him. He is in business for a long time and I did not find a single questionable review about his work in the net, just praise.
    The price ranges, as well as the recommendations about stall speed vary quite a bit. Price range about 1,000$, stall speed from low 2,200 to high 2,800. S&H is always in the 500$-600$ range.

    Some thoughts I still need to sort out:
    1. Crossmember ==> My understanding is, that I can keep the existing crossmember, as TH400 and TH200-4R have the same distance of 27 15/16 to the transmission mount.
    2. Driveshaft ==> My understanding is, that I do not need to modify the existing driveshaft, as TH400 and TH200-4R differ in length (depending on which documentation you refer to) just 1/2 to 3/4 of an inch.
    3. Transmission cooler ==> I am confused why would I need one, my TH400 is already hooked up to the radiator. Do I need an additional one?
    4. TC lockup kit ==> I want the TC to lockup in 4th gear, only. I do not want to mess with a manual switch. CK quoted a kit which I only need to hook to a 12V source. My understanding is, that a pressure switch will be installed in the VB, sensing 4th gear and triggering the TC-lockup soleniod which is also inside the transmission.
    Enough questions for now, I'd be grateful if you can share your thoughts/experience with me. THX, Ralf
  6. 455monte

    455monte Well-Known Member

    I did this swap on my 67
    I started out using a grand national converter because it stalls approx 500 rpm more than a monte carlo converter.
    It was still too tight and in gear at idle the car would jerk due to the big cam. I ended up with a fti converter thats 2800 stall with lock up.
    Ordered thru summit was a lil over 400 bucks i believe. Any converter over stock stall needs an external cooler in my opinion . Heat kills a transmission and extra stall rpm creates a lot of heat!
    So a cooler is always a good addition.
    I use the b and m controller for lock up
    It has a knob u can adjust for which speed u want to power on the solenoid for lock up.
    The 200 trans uses the yoke that a 350 turbo trans does.
    I did either use a forward offset yoke or a longer driveshaft. Cant remember which now. I had a drive line vibration at first due to the shorter yoke engagement into the trans.
  7. hugger

    hugger Well-Known Member

    Yea on the 200r the output shaft must have the correct engagement as the yoke serves as the support for the shaft, that's why the output shaft just flops around. On the turbo hydros the shaft is supported by the bushing in the housing

    Vince built my trans for my 600hp GN it failed but it was due to a design flaw not so much the build quality. Vince is a great guy and very smart trans tech. I wouldn't hesitate to use him again
  8. Cutlass

    Cutlass Platinum Level Contributor

    Theoretically would it lock in every gear, if you set the speed low enough?
  9. Ken Warner

    Ken Warner Stand-up Philosopher

    I think lockup function is only available in 3rd or 4th gear and the trans can be setup/built for only 4th gear lockup. The only reason for 3rd gear lockup in my opinion would be for some very modest uptick is city MPG but you are not likely to see any quantifiable increase. What you will probably find is yourself in situations where it lugs the engine when it locks at low speed in 3rd.
  10. TexasT

    TexasT Texas, where are you from

    AFAIK the brf and tta valve bodies(maybe the bq ones) were the only ones that had the switch for the third gear(all have a forth gear switch I believe though maybe not the early ones that controlled the lock up hydraulically).. Though if you are using that b&m piece any speed could trigger it, the third gear lockup wouldn't be accomplished with other vb unless it was done by speed.
  11. Cutlass

    Cutlass Platinum Level Contributor

    Next decision was made: I decided to go with extreme automatics stage 2 and a 255TC with 2500 stall. Downpayment made, so once the New year comes Lonnie will start building my trans. The B&M controller is ordered and during the next couple of days I will place the orders for the other stuff I need.
    Still missing a decent gear set for the rear, which leads to the question if I should wait with the swap until I find a gear set, or changing to the 200-4R and driving the car with the 2.56 ratio for the time being. What would you do?
  12. ravensbud

    ravensbud Silver Level contributor

    I think that's a good decision. I'm right behind you in making the same decision and based on a lot of reading and customer reviews I whittled it down to Extreme Automatics and Turbo Buick Performance. Pretty sure I'm gonna go with the latter and his full billet unit. Buy Once, Cry Once.

    I'm also contemplating the rear gears...I'll be doing a rear replacement and upgrading to 4.10/11 or 4.30 gears. This'll let me get the most out of it at the track yet still be able to cruise the Interstate comfortably. The .67 overdrive ratio of the 200-4R is just awesome. That's what swayed me away from the Gear Vendors...the .78 ratio just wasn't enough.

    As for waiting for the gear swap or driving it....swap the tranny in and drive it!! You can always keep it in 3rd to avoid lugging the motor, right? That'll give you the opportunity to just worry about getting the tranny adjustments right rather than worrying about the tranny and gears at the same time.

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