C-3

I have a 1977 Corvette L82...
I want to switch the original transmission for a 200R4 and I am wondering if it is just a simple swap of transmission or if they are more mods that need to be done. All the Numbers match on my corvette but I want to take it on longer trips and think the OD will help me enjoy the car even more!
I thought about the 700R4 but I have read that I will have to shorten my drivetrain for it to work.. and Do not want to make any mods like that...
Thanks for the help!

redwingvette

The 200-4r trans will bolt right up to your motor and crossmember.
If you have a TH350 then you will have to remove the crossmsmber bracket. If you have a TH400 then it will bolt right to the crossmember. The yoke is the same for the 200-4r as the TH35o but the TH400 has a larger yoke. If the TH400 yoke needs to be replaced and a offset universal installed on the front of the driveshaft. The universal is a standard self item at most autoparts stores.
The cooling lines can be made to fit the 200-4r with a little bending.
You will need to attach the TV cable to your carb. The brackets to do this can be bought from bowtieoverdrives.com. The transmission shifter will need to be modified for the fourth, OD, gear. BTO also can supply that.
I changed mine a few years ago and still think that is a great mod for the Vette.

The only bracket I did not find a supplier for was the bracket that holds the steering lock cable to the front of the trans. I made one for mine and several others. It is not to difficult to make if you have the tools.

C-3

Thanks for the advice!
I am going to order a Transmission for my vette! I am really excited to be able to take it on longer trips!
How much of a change did you see in your RPMs when traveling on the interstate?
I am going to upgrade the interior.. I am thinking of trying the Sound and heat shield material from mid america.. Hopefully that will cut down on some of the engine heat so i can enjoy the car more on hot days!
Thanks again for the help!

bobs77vet

sounds like you are excited and have a good plan.... take a moment to do some research to fully understand the what type of stall you need in your torque converter and you need to know what your rear end gear ratio is.....then pick your 2004r or 700r4. you also need to understand how lockup works and how you are going to control it. once you fully understand these things you will select the right components for your type of driving

i have the 700r4 and with the 3.08 gears the overall gear spacing is better then the 2004r, if you have 3.30 or more then the 2004r is a better choice. dont worry about the cross members or the shortening the drive shaft those are really small issues to deal with. the overall job of swapping these is not technically challenging but it is a full range of skills.

bobs77vet

77s dont have this locking cable to worry about

Casey71

Hi I have a an 89 700r4 I want to put in my 71, for better low end and the overdrive. For those of you that have the 700r4 was there a noticable increase in the performance off the line.

bobs77vet

oh yeah no question about that .....look at the gear ratios and it will show you how dramatic it is.....then you match those to the rear end and it shows you which of the two trans is better for your car.....with the 3.08 rear end the really steep first gear of the 700r4 is great if you had a 3.33 rear end or higher it would almost be too much. same thing for the top gear the 700r4 is better suited to the 3.08 and the 2004r t the higher rear ends

avner

Transmission Ratio
GM 1st 2nd 3rd 4th Reverse
TH350 2.52 1.52 1.00 1.93
TH400 2.48 1.48 1.00 2.00
200r4 2.74 1.57 1.00 0.67 2.07
700r4 3.06 1.62 1.00 0.70 2.29
4L60E 3.06 1.62 1.00 0.70 2.29
4L80E 2.48 1.48 1.00 0.75 2.08

Avner

Casey71

Yeah I did the math the 700r4 would give me the equivalent of a 4.11 or a 10:1 final drive in first. But I've never done a gear change or driven a car with this kind of ratio. Thanks for the info I found out I do have an 89 700r4 in my blazer, which from what I understand is a good year for that tranny, in terms of splines etc.

macx

I'm planning on replacing the stock 2.87 rear in my 81 with 3.31's and go with a BowtieOverdrive Level 1 200-4R and one of their Level 1 ~2200 rpm converters.

I did a little study with 27" dia tires (255's) and came up with 1600 rpm at 58 mph
and 2200 rpm at 78 mph. That drops me 400 rpm over the TH 350 with the stock 2.87 gears on the road and still gives me a 25% lower overall 1st gear ratio. I don't know that
you'd want to go much lower than 1500 or 1600 rpm for the 55 - 60 mph range.

If you stay with the 2.87 or therebouts, you'll barely be idling going down the road,
esp on 2 lane's, like about 1400 rpm at 58.

Here's a calculator that can figure it out for you.

http://www.angelfire.com/fl/procrastination/rear.html

C-3

Hey just wanted to say thanks for all the advice.
I got a 700r out of a 92 caprice and a tv cable from summit racing.
Been cruising for the last two months.
Used the drive line from the caprice also so I could keep my original.
I did have to shorten and balance the drive shaft but I couldn't be happier.
Put in a new interior and placed my cd player to the top of the lid of the middle storage compartment which kept the front of my car looking stock! Oh used part of a butter knife to be the kick stand to hod my middle lid up... Then just move the stand to the side for it to lower if i am going to be away from the car for a few.
Also put stainless straight dual exhaust on while we were under the car with magnaflow mufflers on the back.
Did throw on a Spectra Air Filter too! I know its not a K & N but after doing everything else I was falling short on cash!
I had saved since I got out of college for this splurg tho.
Didnt have to cut the cross member.
My dad made some type of brace that worked out great!
Tried to post pics of the car but wasn't sure exactly how..
Let me know and I will post.

Trukkurinn

Hi guy´s.
I have a Camaro 68 with a 200R4. It´s a transmission form a Monte Carlo 86, which I had locally rebuild here in Iceland. I used a heavy duty kit from Art Carr. After the rebuild it was perfect in almost any way, except that when I pick or step on the gas so that the transmission changes down from third gear to the second, it immediately responses and shifts down, but for two or three seconds it does not find the third and revs dramatically and then comes in with the third gear with a considerable slip and most often it ends up spinning the wheels franticly which in some cases can be quite dangerous. However, when this happens and I go off the gas and on it a gain, it goes immediately into the third. The TV cable is correctly adjusted and the fluid level is right. It is almost ok when cold, but as soon as it heats up (5 min) it starts doing this. I have already had the valve body rebuild, but no change. The builder thought it was the valve body, but the problem is still there. I don't know if there is any connections, but when it is hot, it always goes into Drive with a considerable clonk. I am a bit lost and no one seems to have a clue what is happening here. If there is anyone out there who recognizes this problem, I would be so grateful if you could help me.
Hope to hear from some genius soon.
Skuli K. Iceland.

johnt365

Hi Skuli,

I know this is an older thread, but I think you will have a better chance at finding a 2004R specific answer on this forum.

http://www.turbobuick.com/forums/transmission-talk.12/

To discuss more here, you might start a new thread.

Hope this helps.

John

Trukkurinn

Thank you John.

fishslayer143

700r4 is a good choice. It will definitely give you the best of both worlds.. be careful the first time you launch it, the tires will light up

mardyn

This will likely be the next upgrade for my car as well... currently have a Turbo 400 which works fine, but desire a few less rpm at cruise and more go power down low.

I think I've got a 3.08:1 ratio, so the recommendation is to go with 700R4 or 4L60 rather than the 200R4?

Seems like the 200R4 requires additional effort to manage the converter lock up and throttle pressure? While the others require different yoke and driveshaft arrangements?

Am I correct in these assumptions?

Thx
mardyn

jersey68l36

[ Seems like the 200R4 requires additional effort to manage the converter lock up and throttle pressure? While the others require different yoke and driveshaft arrangements?

Am I correct in these assumptions?

Thx
mardyn[/QUOTE]

Throttle cable is present in both OD trans. That cable directly controls frt pump line pressure, varying pressure depending on throttle position. Read up on it and you're find that having it correctly adjusted with make or break the swap meaning that attempting to drive with a loosely adjusted cable with fry the clutches due to low line pressure . Likewise converter lock-up is the identical for both, in fact the parts i.e. the solenoid interchange.