200r4 tranny swap

[patrick1151]

I have been offered a wrecked late 80's Cutlass with a 3.8 and possibly a 200r4 tranny. I have looked at the earlier thread on the tranny crossmember that you need to make. Other than that, what other modifications are needed for it to fit a H? Driveshaft? Mounts? tranny tunnel?

Thanks

[littlevega56]

HI, I put the 200-r4 in my 72 vega wagon. All that was needed , was to bump around the firewall. Probley the same as the 350-400 turbo swap. & change the mounting further back on the rear mount. The drive shaft was cut & balanced ? Don't know if you had to do this with the turbo swap.Anyway, I put my engine&trans in at the same time. Just looked easer that way. littlevega

[heinz057]

i have one in my 78 wagon. i had to make a new trans mount and a torque arm mount. i made the torque arm mount on the trans mount. the tourqe arm had to be shortened. you will need a shifter ,the brackets for the tv cable on the carb, and a way to have the loc up work, i used the b&m kit. i also had a new driveshaft made .

[patrick1151]

Is there really any advantage to the 200r4? Or should I just get a BOP TH350 and sell the 200r4? I have heard/read you can get better gas mileage with the 200r4 for and this set up would be for a daily driver, may go in my Sunbird in place of the 262/TH350 if I buy the Spyder I am looking at. Any thoughts? Thanks

[gerbsinmd]

For a daily driver I would jump all over the 200r4. That overdrive can make a big difference. It would allow you to install a little sportier gear in the rear to help with stoplight to stoplight fun, and then when you get out on the road the overdrive will get you some mileage.

As an example, my dad has a 383 in a 80 Malibu, with 3.73 gears. With a TH350 he got around 15 mpg, with a 700r4 he gets 20mpg when he keeps his foot out of it. Yet with all of this it is a high 12.90 sec car. This is with a full interior, full steel body.

[greg72]

Absolutely , go with the o/d trans for a daily driver. The extra gear pays big dividends with regards to cruising gas mileage.

As far as strength, these 200r4s have been living behind heavier, quicker cars than our light h-bodies. Cars like Buick GN's. (and yes i realize there are many h-bodies that are quicker than some GN's ----i was referring to essentially stock set ups ).

From what I have seen and experienced the massaging of the trans tunnel is typically only necessary with the early Vegas 71 -74 maybe later Vegas too , but generally (definitely?) not 75 -80 Monzas , Sunbirds, etc. As the later cars were already clearanced to accept th350 trannys..... and of course the 75 was set up for the anticipated Rotary engine, drivetrain set up.

[rocketride]

Will a stock 200r4 stand up to a 300HP-3.50 geared daily driver or will it need to messaged a little ?
I will be tempted to see if my 295/50's grip the road every once in a while when I get the car together

Jon

[heinz057]

it all depends on what 2004r you have. the stongest stock 2004r are the ones from the buick gn and the monte ss. they have the good servos and the correct valve body.

[rocketride]

I don't have a trans yet. I was going to go with a TH350 but with gas prices as high as they are I'm leaning more towards an OD.

Jon

[283vega]

I've been considering this swap and it's probably the way to go with gas prices where they are.It's not the easiest or cheapest swap but with the overdrive trans you can have your cake and eat it too!The trans length is almost identical to the turbo 350,so many times no drive shaft cutting is needed.The gearing is nicely spaced and the.67 4th gear is great ,it will make up for those rear gear changes.E bay has several companies selling hi perf transmissions for 1200 to1400.

[cammerjeff]

I just finished this swap on my 78 Sunbird wagon, The mod's neccissary depend on what year your car is, and what stock trans it has. The easiest swap will be if you have a T-350 in your car now. If so you won't have to shorten the stock drive shaft, or get a new yoke, your old ones will bolt in. Nor will you have to enlarge the trans tunnel.
You will have to fab up a new trans X-member and torque arm mount, and as previously said I used the new trans X-member to mount the torque arm. I also had to shorten the stock torque arm, so I modified an extra 4-cylinder torque arm I had.
As for the shifter, I got lucky and the stock shifter in my car HAD FOUR forward detents in it already!!!!! and they worked out fine for the 200R4. But if you arn't so lucky you will have to work something out. Also there are several lock up options for the converter. I also went with the variable B&M kit that you can turn on & off or adjust it for speed you wish it to lock up at. I had to buy a short speedo driveshaft to put it in my car, as the tranducer it comes with had to short of a shaft for my car, and the 6" shaft had to make a 90 deg bend that I didn't like.
And as also previously stated, you will have to get the TV cable bracket & adaptor to mount it to what style carb you have on your car. It is extreamly importent to hook the TV cable up with the correct geometry to not damage your trans. This info is readily available on line.
I think you will enjoy the 200R4, it works well with my 3.73 gears, I can now drive the little wagon on the highway again!!!! I was running 4000 rpm at 65-70 MPH, now I am running 3300 without the converter locked up, and 3100 rpm with it lock up. The shift kit I installed is a little stiff for the rear gear ratio I have, and the 1-2 shift almost always squak's the tires even behind my slightly modified 3.8!!!! And the other good feature is the steeper 1st gear on the 200R4.

Good luck with your project, if you wan't I can e-mail you pic's of the trans mount we fab'd up. PM me if interested.

[spyder_xlch]

Nice write up Jeff. And as Jeff pointed out, a properly set up TV cable is a must. I've seen many clutches burnt up because the cable wasn't set up correctly.

[Ti-Beu]

TIRE SIZE, RPM, MPH, REAREND GEARS for the 2004R
23 inches dia tires makes 877 rev per miles X 3.73=3271RPM X .674 (2004R OD)= 2205 RPM. lockup on. J-G

[Ti-Beu]

Sorry thoses RPM are for a speed of 60 MPH. J-G.

[waybad]

I just finished this swap on my 78 Sunbird wagon, The mod's neccissary depend on what year your car is, and what stock trans it has. The easiest swap will be if you have a T-350 in your car now. If so you won't have to shorten the stock drive shaft, or get a new yoke, your old ones will bolt in. Nor will you have to enlarge the trans tunnel.
You will have to fab up a new trans X-member and torque arm mount, and as previously said I used the new trans X-member to mount the torque arm. I also had to shorten the stock torque arm, so I modified an extra 4-cylinder torque arm I had.
As for the shifter, I got lucky and the stock shifter in my car HAD FOUR forward detents in it already!!!!! and they worked out fine for the 200R4. But if you arn't so lucky you will have to work something out. Also there are several lock up options for the converter. I also went with the variable B&M kit that you can turn on & off or adjust it for speed you wish it to lock up at. I had to buy a short speedo driveshaft to put it in my car, as the tranducer it comes with had to short of a shaft for my car, and the 6" shaft had to make a 90 deg bend that I didn't like.
And as also previously stated, you will have to get the TV cable bracket & adaptor to mount it to what style carb you have on your car. It is extreamly importent to hook the TV cable up with the correct geometry to not damage your trans. This info is readily available on line.
I think you will enjoy the 200R4, it works well with my 3.73 gears, I can now drive the little wagon on the highway again!!!! I was running 4000 rpm at 65-70 MPH, now I am running 3300 without the converter locked up, and 3100 rpm with it lock up. The shift kit I installed is a little stiff for the rear gear ratio I have, and the 1-2 shift almost always squak's the tires even behind my slightly modified 3.8!!!! And the other good feature is the steeper 1st gear on the 200R4.

Good luck with your project, if you wan't I can e-mail you pic's of the trans mount we fab'd up. PM me if interested.

PM sent, Thanks TC