TH350 swap to 200 4r?

[chevydog66]

Has anyone done the TH 350 to 200 4r swap? I have read some threads on here about it, but I still have some questions. First, what markings are on the trans to identify it as a 200 4r? Also, I presume that the bell housing bolts are the same pattern in order to bolt up to a sbc. What about the spline count on the output shaft? Will my stock driveshaft slide right in? What about the TV cable? How do I hook that up to a Holley 600 4 barrel? Can I use the same dipstick tube that came out of my TH350? Will I have to modify the trans. crossmember at all? Will the speedo cable screw right in? Can I change the drive and driven gears in the 200 4r in order to correct my speedo? My truck is column shifted, what about the shift linkage? Thanks!!

[killer71]

Hey dude! From what i've studied about these transmissions is that they basically have the same dimensions as our turbo 350 meaning they will bolt right up and you can use the same spline. Suposedly all you may have to do is move the cross member forward if any at all. From what i've read you can keep your same drive shaft (won't have to shorten or extend) Go to bowtie overdrives.com and read their "faqs" about this transmission and this will be helpful. They even have a live chatroom during business hours to help assist you. I will definetly be converting when my pocket book becomes thick enough. Hope this helps.

[chevydog66]

Kewl. Thanks!! I just bought a 200 4r off ebay for $157.50. All I have to do is drive about 260 miles round trip to pick it up.

[Cochise]

Need a picture of the tranny? Transmission pan is not square like the other tranny's.

[killer71]

keep us updated on how the swap goes. Don't forget the pictures!

[chevydog66]

Naaa. I don't need a pic. I just bought 1 off ebay. The guy has 99.9% feedback, so I think I can trust him.

[chevydog66]

Yep. This conversion will get some documentation.

[cooters]

the crossmember is back a few inches from the 350.

[Morgsie]

The 200-4R is an 1/8" bigger than the 350, which should be alright. The mount will have to be moved back 6 1/2" IIRC. 350 yoke should be the same spline. I put a 200-4R in my Impala about a year and half ago, just going by memory here.

[chevydog66]

What do you mean the mount will have to be moved back? Which mount? Or do you mean the crossmember?

[tkeduk8r]

hey, I did it.. way easy and It gets me close to 20 mpg with a 305, 3.73's and 31x10.5s... biggest issues were had to move crossmember back cuz 2004r mounts are more toward the rear of the trans, must use a newer quadrajet or swap throttle shafts in you original so you have the provisions for the TV cable, and then look for a small block donor with the right TV bracketry then order the corresponding TV cable from GM (mine is 81 impala)... you dont need to go through bowtie od's or any other company UNLESS you are going to use your old carb linkage... remember the general put these things in carb'd cars from 81-90 so factory parts are available... one last note... IF you plan on using this as a truck, I would recommend getting the trans prepped for heavvy duty use and run a cooler or runa 4row fact radiator (what i did)... oh one last note I did this in my 74 c10, but the swap should be almost identical. Any questions let me know... Ive run mine for over 2 yeas with no problems...
--MIke

[chevydog66]

I haven't picked up the trans. yet but I was curious as to what the electrical connection that is on the side of the 200 4r was used for, and do I need to hook it up to anything in order to function properly. Also, will my speedo cable screw right into the 200 4r trans? Can the gears be changed inside the trans in order to correct my speedo? Thanks guys!! I cant wait to get started.

[tkeduk8r]

yes the gears can be changed for your speedo, I got a chart off the internet and since i went to a new computer, i dont have that favorite saved anymore, but the info is out there.... the plug onthe side of the trans is to control lockup, you dont NEED it but it will help the trans live longer. If yo-u have the trans freshened up ask your trans guy about getting power to lock up the trans in 4th gear only. The CPU in the donor car did this. I spent big bucks on the kits from bowtieOD, but if i did it agian i wouldnt... there is enough info on the web to be able to accomplish this on our own with a bosch relay and some simple wire mods... do your research and youll do ok... but the kit is out there for around 200 bucks if i remember right and bowtie did treat me pretty good... hope that helps...
--Mike

[chevydog66]

OK, I have ordered my parts and should be receiving the 200 4r trans. soon. I ordered the TVEZ4100, $110, and Completebrake $70, and a drain plug, $7.50. For a total so far of $210.45 from Bowtie Overdrives. I will be starting this conversion in another week or so, and will post some pics and comments as they happen. My 72 GMC currently has a 3.08 rear gear in it, and cruising at 70mph with my 18" wheels puts the tach at about 3100rpm. Hopefully, that rpm will come down to about 2400 or so, just guessing. We'll see what happens.

[ThatOneBlue67]

Trust me... the overdrive is killer! I was wondering, do you know the difference between 200R4 and 700R4? I have the 700.

[combustion]

this might help

http://www.novak-adapt.com/knowledge...on_gateway.htm

[Draggn66]

here's the ttt ya asked fer!

[Foosified]

I am also doing this swap and need a bit of guidance... On the passenger side of the transmission I notice two holes that go down into the pan. One I believe would be for the dip stick, but the other I'm not sure what it is for and it doesn't have a cap or anything for it (about 5/8" dia. and not threaded). Should the hole be plugged?

Second can the shifting linkage be used on the 200 r4? I have a Th350 right now.

What about the Tourque Converter.. do these swap??? I will probably just buy a new one, but thought I'd ask.

Is there some where that has wiring diagrams for the TC lock up??

[chevydog66]

Foosified, Yes, the shifter linkage can be used on the 200 4r. You should use a convertor for a 200 4r. Also, go to www.bowtieoverdrives.com and read about the TV cable, that is what goes in the other hole next to the dipstick tube. The TV cable system is the most important part of the 200 4r trans. If it's not hooked up properly the transmission will not function properly or last long. Bowtie overdrives also has a tech support line that can answer questions about the TV system and torque convertor lockup wiring.

[killer71]

hey where'd you get that good information at? HEHE! How's your tranny project coming along mr chevydog 66?

[chevydog66]

It's done!! She cruises at around 50mph at around 1300rpm. I just need to get the speedo gears dialed in. The trans I purchased was junk, so I had a local trans shop rebuild it. OK, here it goes. I started with a TH200 4r, and some parts from www.bowtieoverdrives.com. I purchased the TVEZ4100 for my Holley 600 carb, which came with a new TV cable, along with the "Complete Brake" kit for convertor lockup. And a drain plug kit. I installed the TV Made EZ system on my carb. Which is a couple of spacer plates and a linkage adapter as well as base plate to hold the TV cable. I had the trans shop install the new TV spring and new wiring kit and solenoid in the trans while they were rebuilding it. I then installed the Brake switch wiring kit, which consisted of a switched 12v wire, inline fuse, new brake switch, and weatherpak connector. This step was actually the hardest. What a PITA!! The brake switch is above the steering column. TIP, squirt some wd40 on the 2 nuts that hold the switch in, so they will turn easily. 34 years of dust and dirt was on mine. Plus, it is difficult to get the 3/4" wrenches in there. Then, I started on actually installing the trans. The torque convertor mounted right up to the flywheel. The bolts screw right into the convertor, no nuts needed. The trans mount from the TH350 will bolt right on to the 200 4r. But, you will have to get some smaller bolts in order to mount it on the 200 4r. The crossmember will need to be slid back to the next set of mounting holes in the frame. I'm sure glad they lined up. I did not want to have to drill holes in the frame. Good thinkin' GM!!! On the drivers side, front top crossmember bolt needs to be installed with the head of the bolt going up thru the frame because there is a rib in the floorpan that makes it impossible to put the bolt in from the top. I tried prying the floor up with a pry bar, but it didn't work. Or, just get a shorter bolt, because after you tighten it up it will be right up against the bottom of the floorpan. Next, the driveshaft slid right in. Note, the pic with the output shaft of the trans. that it is not centered in the middle of the oil seal. I freaked, and called the trans shop and asked them why, because I was able to move the output shaft up and down and side to side. They told me that there is not a case bushing inside of the 200 4r, like the th350 has. I thought for a second that I would have to pull it back out. But, they assured me that it was normal. I then hooked up the shifter linkage, which will need to be adjusted up on the bottom of the column because of the extra gear. I plugged in the weatherpak connector which came with the kit, hooked up the TV cable to the carb. and adjusted it with the D shaped adjuster, while holding the carb at WOT. I then filled the trans with 6 quarts of fluid and fired it up. Checked for leaks. Let it warm up. Checked the fluid again, then got in it and selected each gear, while holding my foot on the brake. I then checked the fluid again, and took it for a test drive. It works great!! But I haven't taken it out on the highway yet. It started snowing here again. I think that about covers it. I might think of something else, and possibly have to edit this later.

[chevydog66]

Here's some more pics. After all that work
Can someone make this a sticky for all of those interested in tackling this.

[chevydog66]

Another pic.
If anyone has any questions, please don't hesitate to ask.

[Draggn66]

Great write-up. I agree this should be a sticky! I'll be using it when I get around to doin my swap!

[Foosified]

Originally Posted by chevydog66

Foosified, Yes, the shifter linkage can be used on the 200 4r. You should use a convertor for a 200 4r. Also, go to www.bowtieoverdrives.com and read about the TV cable, that is what goes in the other hole next to the dipstick tube. The TV cable system is the most important part of the 200 4r trans. If it's not hooked up properly the transmission will not function properly or last long. Bowtie overdrives also has a tech support line that can answer questions about the TV system and torque convertor lockup wiring.

Awesome write up... I'll be using it. Did you notice on the Bowtie site they say to use their spring in the TV system. I'll see if I can find the link.

Nevermind I just noticed the tranny shop put it in for you. Does the spring come with the TV kit or do you have to ask for it??