200r4 Swap

Discussion in 'The Bench' started by blyons79, May 15, 2019.

  1. blyons79

    blyons79 Well-Known Member

    Finally at the point where I can justify upgrading to an O/D trans. I've rebuilt or replaced everything mechanical on my car except the trans. Well that's not entirely true...I bought this TH350 about 7 years ago for $150 and it has been Rock Solid...still is. But I'm screaming down the hwy at 75 or 80 with my 3.42 gears.

    So I'm about to add an O/D transmission here pretty soon. Trying to determine the best route...order the trans and swap kit online or find a local used one and order a swap kit and have it built at a local transmission shop.

    Any benefit by doing it one way vs. the other? Would pulling a core save me any money??
  2. 12lives

    12lives Engage! - Jean-Luc Picard

    I plan to do this. Bought a core but there seems to be little interest from the vendors. Biggest problem I have run across is that most local builders do not believe a 200R4 will last behind a BBB, or even a SBB. They all want me to go to a 700R. So I plan to go with an Extreme based on GN feedback and the price. http://www.extremeautomatics.com/index.php?category=17&searchtext= You might want to discuss the rear ratio and tire size with them. 3.42 might be on the edge for an OD. Also decide about lock up and stall.
    blyons79 likes this.
  3. Bens99gtp

    Bens99gtp Well-Known Member

    ck performance does nice work, and great service. call chris. he knows what it takes to make a transmission live
    Last edited: May 15, 2019
    skylark, techg8 and blyons79 like this.
  4. skylark

    skylark Well-Known Member

    The swap can end up a little pricey, but you won't regret it. I did it a few years ago and I'm glad I did.
    blyons79 likes this.
  5. papa roger

    papa roger Well-Known Member

    Vince Janis in Akron,Ohio is extremely good building 2004R trans.and very reasonable. Built mine to handle 570 HP and 580 lbs ft. Torque with no sweat. With 3.89 gears I can run 1800 rpm at 65 mph with locked up converter.
    v8regalowner, blyons79 and Fox's Den like this.
  6. philbquick

    philbquick Founders Club Member

    My 87 Turbo Regal and my 89 Turbo Trans Am came from the factory with a 200R4. The Regal has a 3.42 rear and the TTA came with a 3.23. Of course tire size is also a consideration.
    blyons79 likes this.
  7. TexasT

    TexasT Texas, where are you from

    I wouldn't waste the time fooling with a local place that does the "race transmissions". I doubt it would go 100miles with one. Just too much difference in the 2004r and the th350/400. If it is assembled by someone who doesn't have a record of others that have lived you are wasting your money.
    The shops mentioned above all do excellent work. And if you have the desire you could probably assemble one yourself but it will take some effort. I think if you can remove and replace one you have the ability to overhaul one. But it will take some additional tools you probably don't have. The tv cable and its setup is crucial to making one go. If it isn't adjusted correctly and the pressure doesn't rise instantly with the throttle it dies quickly, because the pressure is what applies and keeps the clutches engaged and not slipping. Slipping clutches become burned clutches and it spirals down from there.
    3.42 with a 26" tire is what the turbo regal came with. Should be fine. The cross member will have to be moved back to the th400 holes. Then the decision to go lock up or non lock up for the converter.
    Billet shaft forward drum and dual feeding the direct clutches should be seriously considered and I would think mandatory with over 500hp/tq. There are other things that can be done to gain longevity.
    Lots of good info over on turbobuick.com in the trans section. Let me know if you want any of my suggestions.
    blyons79 and steve covington like this.
  8. Fox's Den

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

    Vince Janis did mine back in 2005 still running strong.
    blyons79 likes this.
  9. wovenweb

    wovenweb Platinum Level Contributor

    There is a thread around of someone here in Texas who used a shop locally (Austin area maybe?) to do their 200-4R rebuild. I used Jim W. for the rebuild along with a torque convertor. I'm still working on paint and body so don't have much experience to share yet.

    *Now that Ithink about it, it may have been here or the Pontiac site (PY Forums - maxperformamce.com)
    blyons79 likes this.
  10. blyons79

    blyons79 Well-Known Member

    I was hoping to be in the $2k range. Looks like it will be closer to $3k when all is said and done. Boy I'm getting cold feet now. Found a core a few town over on craigslist for $150. Think I may try my hand a rebuilding one. Lots of detailed videos on youtube.
  11. jmos4

    jmos4 Well-Known Member


    I can understand the cold feet, 3800 for a quality trans can make anyone rethink a OD. I have a project in the works and been doing the same debate, th400 and lower gears look like less hassle but lower rpm would be nice.

    blyons79 likes this.
  12. philbquick

    philbquick Founders Club Member

    They did part of a 200R4 rebuild on Wheeler Dealers this week for a 71 Chevy C10. It doesn't look that bad.
    blyons79 likes this.
  13. gs66

    gs66 Well-Known Member

    I’m always debating changing to and overdrive trans or adding a Gear Venders unit too. Seems like everything winds up being around $3000. Sure hear good things on the Power Tour though from guys running OD.
    blyons79 likes this.
  14. blyons79

    blyons79 Well-Known Member

    Exactly. I wanna be able to jump in my old steel stamped car and drive 500 miles at a minutes notice without breaking a sweat. As it stands, she’s a fair weather, short distance friend.
  15. 69a-body

    69a-body Well-Known Member

    Jake's performance in Sanger used to build them, but he has shifted to 4l80e builds. His website doesn't list them anymore.
  16. TexasT

    TexasT Texas, where are you from

    Jake is a good guy. He might do one if you have a decent core, but he makes those calls.

    Nothing wrong with a DIY approach. Not difficult but does require some patience and attention to detail.
  17. Bens99gtp

    Bens99gtp Well-Known Member

    if you have a good trans your happy with the way its shifting why not just do a gear vendors. they fit very easy in most tunnels, it's as simple ss removing the drive shaft, removing the extension housing, install the provided adapter, then bolting the 8 bolt to the od unit. having the drive shaft shorten, then some very basic plug and play wiring.

    the have the wired parts colored and plug straight into the module with what looks like phone plugs. then a switch on the floor and 1 on dash. the install and wiring should take less than a day by most ppl.

    it will out live the trans and you can turn your 3 speed into a 6. having a 2nd gear of is nice when you dont need all the revs of a full 3 to 2 down shift
  18. Fox's Den

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

    I spent about 2300$ back in 2005 when it was all said and done. The torque convertor was an expensive item that one cost me 800$ It is a 3000 stall with lockup the one I used was Pro Torque. I got a good deal from Vince on the trans since I knew him a lot of years and has done my 350 on a few occasions.

    I can lock it up manually with a switch so you can lock it up in 3rd gear when driving at 35-50 mph before going into 4th gear. If going to get to 4th gear I keep it unlocked until then.

    I used this trans with nitrous on several occasions and ran in the high 11's so the trans can take the abuse. Since then I have backed off the nitrous so I am not as hard on the parts, plus the motor is 25 years on rebuild now I keep it in the mid 12 range now as seen in my sig.

    I never went with the Billet drum and the trans is fine. I guess if you plan on going faster than 11.80 like I did a bunch of times then I would have that done. Your 350 engine is never going to break it so don't worry about it. I made 420 Hp and 450 TQ on a rear wheel dyno with the 125 nitrous shot so that is over 500 on the motor and I never broke the trans.

    I had to have a new driveshaft made as the stock one could not handle the big nitrous shot. Tore that sucker in half.

    I did the trans change at this time and just had to measure from back of the trans to the rear, sent the measurements and they made it to spec. I also had Spicer U-Joints put in too as they are a lot stronger.

    Worth every penny don't second think it, probably will be a 3 grand upgrade now.

    Never had a problem again.
    Last edited: May 18, 2019
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