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 tranny swap: TH350 to 200 4R
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jdkopveiler
Tribal Scout

7 Posts

Posted - 02 Jan 2007 :  8:58:14 PM  Show Profile  Reply with Quote
I am thinking of swapping out my TH350 tranny for a 2004R in my 78 TA. Will a stock tranny with a shift kit hold up for the long haul in my daily driver with 3.42 gears (posi) and a mild 400 (300+ h.p.), or would I be better off sticking with the one TH350? I have read that the overall length of these trannys are close enough to use the same driveshaft. Is this true? Also, what other problems will I encounter...crossmember, shift linkages, kickdown cables, etc. Thanks for the help!!!!!

mkpontiac
Two Feathers

56 Posts

Posted - 02 Jan 2007 :  11:51:29 PM  Show Profile  Reply with Quote
jdkopveiler

I saw this company advertised in I think it was High Performance Pontiac.
http://www.bowtieoverdrives.com/index.shtml
200R4's can defintely handle 300+ HP if they are built correctly. As to your other questions I wished I had the answer since I have considered doing the same thing. A 700R4 is another option.

mkpontiac
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Phil
The Great White Buffalo

USA
7303 Posts

Posted - 03 Jan 2007 :  11:02:15 PM  Show Profile  Reply with Quote
I run the 200-4R's in my 72 Formula and 70 GTO. Both are 400 Pontiacs. The Formula is modified for street performance while the GTO is stock. These transmissions have performed flawlessly. The Formula trans came out of an 87 Buick GN. I installed that one the day of the Indy 500 in 1989! It ran perfectly for years. I had it redone only to prevent a failure of the stator support, which was then upgraded to the (now common) hardened stator support.

There are very knowledgable forum members here that have worked on these trannmissions and can provide further guidance if you go that route. But I must caution you that while well intentioned, some will try to discourage you by pointing out the shortcomings of these transmissions. The key is to dissect all the information and remember that some folks are looking at this transmission purely through quarter mile racing sunglasses. But many of us use our cars for mostly street performance driving and for weekend fun. Frankly, if I was running my cars mostly at the track, I would not waste money running an overdrive trans. The street is where they really shine. That being said, be prepared to spend a good amount of money doing the swap in order to get a properly prepped transmission. That was not a drawback for me as the advantages far outweighed the cost.

A properly built 200-4R can handle a substantial amount of power, far exceeding 300. Further, I have observed many Buick GN's, GNX's and Pontiac Turbo T/A's putting serious horsepower through these transmissions and running incredible quarter mile times. Overall, IMHO the 200-4R seems to hold up better than the 700-R4 on the street.

The 200-4R has a better gear spread, is exactly the same length as the short-tail turbo 350, fits into vintage Pontiacs without a ball peen hammer, and shifts to 4th gear at full throttle. A friend with a highly modified 5.0 Mustang and a custom AOD trans found out the hard way one night on a deserted highway about the 200-4R's special talent for full throttle upshifts. He was so disgusted, he immediately ordered a conversion kit from Art Carr to install a 200-4R in his Mustang.

Your stock turbo 350 driveshaft/yoke can be reused with the 200-4R. Cooling lines need a slight tweak bending and will screw right in as well as the speedo cable. The 200-4R has a universal (dual flange) bellhousing.

Conversely, the 700-R4 has a Chevy only bellhousing, requiring an adapator plate. The 700 is longer requiring a shortening of the driveshaft and rebalancing. The 700 does not give you a full throttle upshift to 4th gear, requiring lifting of the throttle to upshift. Upshift valves like B&M's and the Corvette valve provide a small gain but still do not provide the full throttle feature like the 200-4R. Nothing like putting the hammer down and holding it there, watching the car head to 140 with ease long after shifting to 4th gear automatically. The 700 has a poor 1st-2nd gear ratio, which was designed to get the "no low end torque" small block chevy and 4.3 V-6's off the line with a short first gear (3.06). The 700 has interference with certain areas of retrofit cars, requiring redneck massaging in some cases, although not major.

No kickdown cable on either OD trannys. They use a TV (Throttle Valve) cable, and must be set exactly correct or certain trans failure will occur. Not a big deal as most aftermarket companies now offer throttle brackets with the correct geometry to simply bolt on and snap cable into place. Higher horsepower generally calls for a non lockup converter. Just good insurance. Slight modifications to the pump are required if switching to a non lockup convertor. I run factory lockup converters from the Buick GN and 89 Turbo T/A in mine and they are stock GM. The best factory converter for these trannys IMHO. Aftermarket seems to favor Continental converters, and will be my choice down the road for my next upgrade.

Slight mods to the crossmember are required, metric bolts for trans. but you can use your original rubber mount if it is in good shape. Your flexplate is drilled for the stock 350 converter if original and is also a direct bolt up for the 200-4R converter.

One of the best mods I ever did to my Pontiacs. BTW, the wifes Buick GN runs in the 11's on the spray with a 'Transmission Specialties' 200-4R basic upgrade (done in 1988) and stock GN lockup convertor. This trans now has over 80k miles and still shifts tight as the day it was installed! And although this car is garaged and pampered, the car is a balls to the wall street performance car and has always been driven that way.

My Turbo 400's never performed that well for that long of a time period...

Great swap and easy to do. Only caution is to start with a good core (1986 and up) out of a Buick GN, Turbo T/A (good luck), Turbo T-Type, with a second choice being the Monte SS, 442 Olds.

I have no personal experience with Bowtie Overdrives but for what its worth, I have heard positive remarks from both Chevy and Buick friends.

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.
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Drew W
Sitting Bull

USA
123 Posts

Posted - 04 Jan 2007 :  1:07:56 PM  Show Profile  Visit Drew W's Homepage  Reply with Quote
Why a non-lockup converter with a hi HP engine?
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Phil
The Great White Buffalo

USA
7303 Posts

Posted - 04 Jan 2007 :  4:30:03 PM  Show Profile  Reply with Quote
Drew, the non lockup convertors are generally accepted as stronger and less failure prone in high horsepower applications. As much as I like the OD trans, I do not buy into the claims that they can handle 800 horsepower. My experience is that there are some companies that make exaggerated claims and charge sky high prices for these transmissions.

Having said that, I prefer a good solid lockup converter for the street, and it pays dividends especially with a higher stall. But of course, I am not in the 5-600 horsepower club...yet.

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.
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mkpontiac
Two Feathers

56 Posts

Posted - 04 Jan 2007 :  11:39:37 PM  Show Profile  Reply with Quote
Phil

Can the stock shifter be used with the stock P,R,N,D,2,1 shift selections or are modifications or a new shifer required? Are the modifications required on a TH400 similiar to what is required on the TH350?
Mark
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Cartman
Cochise

USA
224 Posts

Posted - 05 Jan 2007 :  01:45:35 AM  Show Profile  Reply with Quote
Companies like OPGI sell kits to modify your current three speed auto shifter for use on four speed autos. these include new detent plates and shift indicators. slight welding is usually required.
http://www.opgi.com/product.asp?ProdCode=G221531&topcatid=70&grpcode=22055&yearrange=&chapterid=1038&topvalue=

Hippies, they say they want to save the world, but all they do is smoke pot and smell bad.
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Drew W
Sitting Bull

USA
123 Posts

Posted - 05 Jan 2007 :  09:19:55 AM  Show Profile  Visit Drew W's Homepage  Reply with Quote
Phil,

I'd be interested in knowing where 2004R's typically fail on higher torque cars. Also if these points of failure can be improved on for, say, a 500 ft/lb engine.

Can a lock-up converter be installed so that the lock-up feature could be disabled for occasional racing?

Drew
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Phil
The Great White Buffalo

USA
7303 Posts

Posted - 05 Jan 2007 :  10:31:02 AM  Show Profile  Reply with Quote
Drew, I use a B&M lockup kit (not the cheap common one) which includes a speed sensor and an adjustment knob. I can dial in the speed which I want the torque convertor to lockup. This IMHO is much preferred over the less expensive kits that just lockup the convertor as soon as the trans shifts to OD (4th). A mid level way of doing it is to use the vacuum switch inline with the pressure sensor in the 4th gear pressure tap on the side of the trans. But I never liked the vacuum switch as it is not adjustable and you get illogical locking and unlocking.

The speed sensor and adjustment mechanism is slick as I can set mine anywhere between @ 30-90 mph. I usually keep mine around 50 mph, to avoid surging from the choppy cam in 4th gear at low rpms. But you can constantly adjust it from the dash mounted dial depending upon your setup. If I find myself in a sudden street race, I just swing the dial up to 90 mph so that there is no chance of locking up the convertor. This is also what I do on the track (that I only frequent on average every 5 years or so).

It is not that you can't get a lockup convertor to hold up to high torque, it is just more expensive and according to many who actually build these trannys, the non-lockups are still more reliable. It is sometimes difficult to draw a clear picture for some folks since many are only focused on pure drag strip action, whereas 95% of my driving is street pleasure, albiet spirited driving with occasional full on assaults. Big difference and may be why I have not had the problems with the lockup convertors that others have had. But many of my Buick buddies run these with lockups and no issues whatsoever. Like everything else, some people have problems and others don't. Could be the driver, the builder, the parts manufacturer, the combination of parts, the car is too heavy, lack of maintenance, too much heat, inferior quality of materials, who knows?

But I do know that I am not so comfortable with the idea of this transmission behind my new 455 engine once it is completed. But I will run it and see how it does. May be a 5 speed manual in my future after all...

The shifter is easily modified by changing the detent plate in the shifter. I used one out of a Monte SS and believe it or not it fit perfectly in my 70 GTO shifter. Gotta love the General! Just drilled out the two rivets and when I replaced the detent plate I used two small bolts with lock nuts. Worked perfectly. I modified the stock cable and brackets and used an indicator plate out of a mid 80's IROC-Z shifter. But as Cartman said there are alternatives just a phone call away. Shiftworks would be my first choice as I have dealt with them before. Also, I suspect they are the supplier of the other companies that carry these parts.

On the 72 Formula I used a B&M Quicksilver console shifter. These aftermarket shifter companies finally got their brains in working order and now make shifters that accomodate 3 & 4 speed autos all in one box!

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.
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Ron1973
Two Feathers

USA
62 Posts

Posted - 09 Jan 2007 :  3:07:32 PM  Show Profile  Reply with Quote
Great info Phil, I've always heard that the 700 was the more preferred of the OD trannies. I also was considering doing this swap in my 73, but was not sure how much power one could handle. I have a turbo 400 in it now, but I'd really like an OD transmission. I was considering one of the Gear Vendors units. Can a 200-4R be built to handle 600 ft-lbs?
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jdkopveiler
Tribal Scout

7 Posts

Posted - 09 Jan 2007 :  8:04:14 PM  Show Profile  Reply with Quote
Thanks for all of the GREAT info Phil...it been a big help! I have one other question that I don't quite understand though. The 200 4r that I have is out of a 1988 vehicle, and I was told that from '86 on, they used a converter that locks up electronically, and therefore would not work in my '78. Is this true, or is there a way to get around it? Thanks again in advance!
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Phil
The Great White Buffalo

USA
7303 Posts

Posted - 10 Jan 2007 :  12:50:25 PM  Show Profile  Reply with Quote
On the 600 ft lb. question, I am hoping to find out the hard way soon. Certainly there are vendors who make those claims, and judging from some of the Buick GN's, Turbo T/A's and even older cars retrofitted with the 200-4R, it seems as though they handle alot more than I ever expected. But expect to pay alot more as you go up the torque capacity/horsepower scale. Remember the old adage: "Horsepower costs money, how fast to you want to spend"?

On the lockup question, the convertor locks up the same way, but the newer vehicles used the computer to send the signal to lockup. The fuel injection cars tied it into the TPS (throttle position sensor) so that everytime you let off the gas, the convertor would unlock, then relock once you touched the accelerator again, such as one would do cruising down the interstate in heavy traffic.

But really the transmission part of the lockup world was the same, with the same square plug on the side. The trans is only looking for a 12v signal at a particular terminal in order to lockup. What sends the 12 volts is of no concern to the transmission. In our retrofit world, that is usually not a computer, but rather a switch of some sort.

Hope that helps...

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.
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Don
Two Feathers

USA
54 Posts

Posted - 02 Feb 2007 :  9:39:47 PM  Show Profile  Reply with Quote
Phil
I have a 2004r in a 65 gto with the stock afb carb, I'm haveing alot of trouble adj the tv cable. They don't make any kind of kit to fit the stock 65 afb that i know of do you? I have talked to TCI and Bow tie and neither one can help me They said i would have to make up something> Do you know of anything out there?
Thanks Don
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Phil
The Great White Buffalo

USA
7303 Posts

Posted - 03 Feb 2007 :  2:52:53 PM  Show Profile  Reply with Quote
Don, check out the Edelbrock brackets for their AFB clones.

Can you be more specific as to the type of adjustment trouble are you having?

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.
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Roadrage David
Cochise

Netherlands
265 Posts

Posted - 04 Feb 2007 :  02:55:22 AM  Show Profile  Reply with Quote
Here we go again!! chek out 8 posts douwn to 455 cam recomodation. go to my post where it sais nothing wrong with a 455 with 274xe click the link for the video . 500+ hp testing a 2004r level 3 from bowtie overdrives..........
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Phil
The Great White Buffalo

USA
7303 Posts

Posted - 04 Feb 2007 :  12:07:14 PM  Show Profile  Reply with Quote
Dave, I saw the video the day you posted it and complimented you on it. I realize the 274 is OK with my combo based on numerous replies on the "455 cam" post, however it may not necessarily be the "best" pick for my exact combo. Then again it may be, that is the feedback I am looking for.

But considering some of the feedback I got, I am seriously considering a streetable hyd. roller now. I still have my doubts about the long term reliabilty with the 200-4R in a heavy car with high torque, but as previously stated: I am going to find out and have fun doing it!

Keep those cool videos coming, I really enjoyed it!

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.
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Roadrage David
Cochise

Netherlands
265 Posts

Posted - 04 Feb 2007 :  3:58:39 PM  Show Profile  Reply with Quote
Phill i didnt meen the engine pacage just pointing pout towards the tranny, but now we are on it my own cvms engine hase the xe284 it hase more hp and rpm then the xe274. altho the formula hase gobs of torque it kinda lacks the upper rpm at high speed with the tr2004r and the 3.42 rear ratio to keep on ecselerating at high speed.dont get me wrong it defenatly hase its forward momentum, but a 3.73 ratio ore 30/50 more hp and 800 more rpm. would make a lot of diferends going ore keep acselerating into and past the 250 kmh mark ..
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Don
Two Feathers

USA
54 Posts

Posted - 06 Feb 2007 :  8:35:34 PM  Show Profile  Reply with Quote
Phil
I'm haveing trouble getting a brkt or some method of connecting the tv cable to the carb. Tha stock carb has to long of travel and i either get to mutch trans pressure and hard shifts or i get stack shifts if i slack it off. Also can't get the right height on the linkage to get the right arc.Bowtie said i would have to make something up. Trans is great the only problem i here is everyone is a problem adj the cable
Don

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dgray
Crazy Horse

845 Posts

Posted - 07 Feb 2007 :  09:10:11 AM  Show Profile  Reply with Quote
Please check out this website. Lots of good info on transmission changes, including the problems that you are having. http://transmissioncenter.net/highperflist.htm I'm thinking of going to an OD tranny also. Good Luck, D Gray
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Phil
The Great White Buffalo

USA
7303 Posts

Posted - 07 Feb 2007 :  09:43:42 AM  Show Profile  Reply with Quote
The pivot travel of the throttle shaft should not vary much because all carbs open butterflies from closed to (@90 degrees or <) full open. You may be mistaking travel of the bellcrank as being too much when it may be just a longer bellcrank from pivot to end. You really have to check the angle of the shaft from full closed to full open. If your shaft is going past full open, you may want to limit that since your butterflies would be going past full open and possibly inhibiting performance.

You would want the same distance as a factory 200-4R car from the pivot point (throttle shaft C/L) to the C/L of the attaching pin for the TV cable. I try to mimic the angles too. Usually some trial and error to get it right. You may have to drill a new hole in the bell crank on the carb to get the correct distance from the pivot point.

A bit easier these days with Edelbrock, TCI and others making universal brackets for us. They usually just need some minor tweaking and patience to get them to work on our Pontiacs.

I put the OD trans in the Formula back in 1989 and there was nothing available except for naysayers galore! I fabricated a bracket from scratch and cleaned it up with a dremel tool. Later years, I made a new bracket out of aluminum which looks much nicer and cleaner. I got lazy with the GTO and just used a Summit Universal kit and tweaked it a bit.

I try to position the location relief such that the adjusting tab is in a convenient location for adjusting the TV cable. Seen too many upside down and wonder what the installers were thinking.

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.
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Christ
Howling Wind

USA
1808 Posts

Posted - 07 Feb 2007 :  11:21:29 AM  Show Profile  Visit Christ's Homepage  Reply with Quote
If your going to spend 1600 + for new tranny and you have abuilt turbo 400 wouldnt it make sence to go with the extention 6 speed unit that attaches to the turbo 400?
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