Rebuild 231 or by 350

[Don's 77 Sky]

Randal, was there any mods that you had to do to install the 2004 transmission, you know like the drive shaft or shift linkage, torque converter. I am really interested in the possiblity of putting that transmission into my car. Mileage is the key to me keeping this car, if I can't improve its mileage I can afford to run it and will have to stick with my escort or look for something else and sell the Buick. Get back to me ASAP. Thanks

[Randal]

As long as you have a Hydromatic 200 in the car now (I believe all 3.8's came with it), the 200R4 bolts right in, down the the driveshaft, bellhousing bolts and torque converter. The toughest part is the lock up converter. If you know a guy that works on GM transmissions they should know how to build the 200R4 to lock the converter up automatically in 4th gear(with a 12V power source), otherwise there are products out there to simulate the computer controlling of it. It is a guarenteed 33% lower rpm not including the slip the torque converter used to have. My 3.8 runs well, but gets crap milage (I think it is the cam) and I went from 15-17mpg on the highway to 22-24mpg. A better example was in my '69 Firebird 400, I went from 17mpg to 28mpg (fuel efficient cam) with the swapping of the transmission.

[Randal]

P.S. A fuel efficient cam generally gives good low end torque which is the feel of responsiveness at low engine speeds. So if you rebuild the engine and get a good torque cam you should be satisfied with the power feel so long as you are not really quarter mile racing.

[the skylark]

Don, I'll start with the freon question. The proper way to update is to have the system evacuated, flushed thoroughly. and recharged with R134a refrigerant. Cars with small condensers (shouldn't be a problem on yours) may need a small add on electric fan to keep good airflow across it. On the engine question, when you overheated you could have cracked a head adding a little more to your rebuild. Other than turbo 3.8's I'm not sure if there were any fuel injected RWD 3.8's made, but if there were and you were lucky enough to find a whole car say wrecked in the rear but good running and emission compliant, you would need the wiring harness and all the sensors and the computer and the matching transmission as a complete set. Seems like a lot of trouble, I know, but if it was done right would make plenty of power compared to 77 231 and far better gas mileage and driveability than either of those carbureted engines. Of course if you used a turbo engine combo out of say 86/87 Regal, your 77 would scream and get great mileage when not screaming too much. Trouble for me would be keeping my foot out of it.
Dan

[Don's 77 Sky]

the Skylark,

I appreciate the insite! I have gotten away from changing the motor, after some investigation and information from this site, its more then I want to do. So rebuild and slightly modify or hop up the 231 is the path I am looking to...presently I am searching for a 200R4 trans at a resonable cost and some type of warranty.

I have talked with some other people and they tell me about some linkage geometry that must be right or I could burn up the trans..any thoughts on that. I don't have much knowledge on this and overdrive transmissions.

Once the transmission is installed I understand that the rear mount will have to be modified or changed to fit the new trans. Any one have any knowledge on a So Cal trans place that could do this type of upgrade and make sure all is correct?

I really do appreciate all of your suggestions and support. Thanks again.

[Randal]

The only linkage change is the Throttle Valve Cable (TV Cable), the original 200 comes with a down shift cable and works on a different principle than the TV cable. Unfortunately I did/do not have the stock linkage holder for the accelerator and TV cables, so I am not sure if the stock linkage bracket will work or need to be changed to a mid-80's carburetated 231 bracket. But once installed the TV cable needs to be adjusted properly for the proper shifting and to keep from burning up the trans. I recommend having a transmission person either teach you how to set it or have them set it up for you. I had the benifit of working at a new car dealership at the time, so our tranny guy helped me out with it. As for the cam, I still recommend a high torque/high vacuum one for the efficiency.

[Don's 77 Sky]

Ok guys, you won't believe it, I finally understand what you have talked about the TV cable...I found a site that told me all about it...now I can move forward. Feeeewwwww, I was really starting to get worried over the TV cable.

But at www.bowtieoverdrives.com, they all the info..and with the visual help it will really make things a lot easier.

I really appreciate all your help and information, I know I have said this a lot, but you all deserve the praise and thanks for your information and support. Know if the holidays will come and go I can get started.

Thanks again.

[Randal]

Best part it is all free of charge, Buick On Man [img]tongue.gif[/img]

[Don's 77 Sky]

Well the Holidays will soon be over and now with the Santa Ana's blowing, it almost makes me want to start on the rebuild. But I will just have to wait another couple of months for solid weather. I hope all of you have a great holiday seasons, and you have the best of New Years.

[81limitedT]

I agree w/ your wish to put a TH200r4 into your 77. I'd someday like to do the same OD swap for my Regal. Aren't The Th200/200r4/350 all the same overall length and direct swaps for each? I think I have some info that might help you or others in their search for this combo.
I'm not sure when GM started building the TH200,
but all 3.8s didn't come w/the TH200. My family's owned several 80-86 g-bodies and 5 had 3.8s'
My 81 regal limited coupe has a 3.8 2bbl/ TH350c,
Grandpa's 80 Cutlass 4dr had 3.8 2bbl/TH350,
my 80 MonteCarlo cpe had 3.8 4bbl Turbo/TH350,
the 85 Cutlass Supreme cpe had 3.8 2bbl/ TH200c,
and my 80 Cutlass Supreme had 3.8 2bbl/Th350.
My TH350c was rebuilt to Turbo6/V8 Spec and runs great (slightly stiff shifts) in my Regal. I used to get 22mpg hwy when I bought the car w/ 68k, but it went downhill as the car has aged. I made a sacrifice for low speed to gain mileage on the hwy when I swapped the 2.41 posi from the Monte Carlo Turbo for my 2.73 open rear. It runs great for cruising without the OD , but it's slow around town and kinda a gas pig in stop n go.
Don't know if this helps anyone, but hopefully...