71 Cutlass

If I replace my TH350 for the 200-4R, can I keep the torque converter and shift kit from the TH350? I have never had to think about an OD transmission (therefore know nothing about their internals), but like the idea of installing one b/c of my 3.42 gears and the freeway driving I have to do.

extreme1

No and No, valve body's will be different and the 200R4 uses a lockup converter.

71 Cutlass

Thank you. Recommendations on a converter? Currently using a TCI converter with a 2500 stall speed.

BlackGold

You could use the stock converter that came in the mid-80s 442s. (Off the top of my head, I think it's known as a type "D5"?) Behind the 442-version of the 307, these stalled at about 2400 rpm. Behind a stock 350, I would expect it to stall just a little higher. Should be good.

However, you really should consider beefing up any TH200-4R you intend to put behind a 350. Most of them behind 307s required a rebuild sometime in their lives. You'll be living on borrowed time if you don't beef it up.

68conv455

I have a modified "D5" in mine from CK performance. D5's were in grand nationals. Not sure about 442's. My souped-up 2004R is also from CK. I'm running 3.55 gears in back and really like how the car crusies when in Overdrive.

Olds64

You should be able to source aftermarket parts for your 200 4R from Summit. I'm not sure what internal modifications are done to "beef it up," but parts are readily available.

joe_padavano

The go-to guy for 200-4R parts and expertise is Chris at CK Performance:

http://www.ckperformance.com/resourc...SMISSIONS.html

He caters to the turbo Buick crowd and has the parts to allow these transmissions to survive in a 9 second drag car.

71 Cutlass

Will try CK. Those who have used them appear to be satisfied with what they have received. The local guy who did my TH350 said he "wanted no part of it" when I asked about the overdrive.

Olds64

Too bad your local transmission guy didn't know anything about it. Overdrive transmissions aren't that much different than your standard TH 350 and TH 400.

joe_padavano

That's the truth. The only fundamental difference is an additional clutch pack and an additional planetary gearset. The parts aren't any different than in a non-OD trans, just a few more of them. Now, if he's worried about warranty work due to the fragile nature of an unmodified 200-4R, well, then I can understand that. I'm still amazed that I fragged TWO of them with a pavement-ripping VIN Y 307...

Then again, both of those were rebuilds of unknown quality. The 200-4R in my 84 appears to be original and has about 120K miles on it. The one thing to be aware of is that the 200-4R is very susceptible to heat. Be sure you have a good aftermarket trans cooler plumbed into the system.

geckonz08

mighht be a good idea to invest in this manual.Cheap insurance ?!

http://atsg.com/cart/products/200_4R-11-5.html

mike

olds455

i can vouch for Chris at Ck as well. I just rebuilt my own 200 4r with his book,parts and help. I had him build a 2800 stall lock up converter for it and it works great. The car doesnt drive well locked up because of the big cam so im going to sell it or have him rebuild it for non lockup. I used Chris for all my 200 4r needs and answers. Good luck. its an easy trans swap.

therobski

OLDS45 this sounds stupid but what's the difference between a lockup and a nonlockup if both trannys are in OD?

olds455

Just a couple hundred rpm. The lockup will go one to one like a normal clutch. The non lockup will have some slip like the th350. As for the parts I'm not quite sure but the non lockup needs some changes made to the pump and converter. Fourth gear acts the same both ways. I ran my car in forth unlocked buy feared it would heat up and damage it so I would lock the converter or shift to third.

joe_padavano

All of the stock GM overdrive automatics use lockup converters. You can get a non-lockup conversion for these transmissions from the aftermarket, but you need a different converter at a minimum and possibly a pump. I can't think of a reason not to use a lockup converter for a street driven car.

Olds64

If you are worried about heat damaging your transmission you can install an aftermarket transmission cooler. These are readily available and easy to install.

olds455

Yep I'm running a aftermarket cooler and the radiator cooler as well. I've read about running in fourth without the lockup converter being locked so it produces more heat. My engine lugs to hard in fourth gear at any rpm below 2000. So I left it unlocked around town in third gear. I believe it's because the high duration camshaft.

68conv455

My CK transmission is set up to only lock in 4th gear. Chris also told me to never run the TC locked at WOT.

olds 307 and 403

Just like anything, luck of the draw. My stock 2004r has hardened pump rings, stiffer pump spring, Big trans go shift kit, Bowtie(yuck) over drive billet servo, Hughes deep pan and 700r4 filter with an extension. I need a different governor, mine few apart at the track. A modified GN one will replace it. I have the generic 2000-2600 stall converter, mine stalls on the lower end. The D5 stalls less than the advertised 2400, according to others. CK is supposed to be good. Extreme automatics are also supposed to be good and affordable too. I have a 403 pushing 350 ft lbs of torque, so far, so good.