Need some guidance on 200r4

I have a Buick 350 with a th350 Hughes performance 2200-2500rpm stall and 3:42 gear in the 8.5 diff. The cam power range is 2500-5000rpm (looking back I wish I chose more wisely on the cam).
Currently rolling down the highway at 70mph the car is at 3000-3200rpm and about 2500rpm at 55-60
The transmission I want to inquire on is out of a Monte ss. 200r4 czf code owner claims it has 56,000 miles wants $550 for it has no torque converter. My questions are, should I still run a 2200-2500 stall or could I go lower. Is there things to look at if I buy it? Will it bolt up to the Buick and do I need a Buick pattern torque converter? the car has 300-350hp now and it is a street car only. Any info would be greatly appreciated. Josh

 

The rear end ratio you have is perfect for a 200R4. They can be built to handle 600 hp, there are hardened parts if you're going to race. 2,200 stall would be good, the 200R4 also locks up and it can be set up to lock up automatically once it goes into overdrive with 12V connected to the transmission. I have one built by a shop that has internal lock up with no 12V applied to the transmission, but, I don't know how he did it. Maybe some other members can shine light on that. You're going in the right direction.

 

The th-350 torque converter won’t interchange to the 200 trans. Yes it’s a very easy swap, and yes the trans bolts up.

https://www.v8buick.com/index.php?threads/th350-200r4-swap-summary.176591/

 

So should I go with a 1800-2200 stall or 2200-2500 do I need to worry about the converter slipping at cruising speed? or once it locks up it's fine. In OD what cruising rpm could I see? Any guess

 

If you are cruising at 3,000 RPM now, it will drop to 2,000 RPM with the 200-4R since it has a .67 overdrive. Just multiply your given RPM by .67 to get your new RPM in overdrive.

If you get a converter and you aim to keep the same cam, I'd get a good lockup unit that stalls 2,500 RPM behind your small block to keep the cam from being a dog.

Another advantage to the 200-4R is the first gear is lower.

I have mine set to lockup in 4th gear after 10 seconds and it feels like a 5th gear. It drops another 200-300 RPM when that happens.

 

Yes it’s not a big deal if you have a high stall as the lockup gives 100% lockup when cruising. I once had a truck with a 3000 stall and it really helped the heavy truck launch off the line without too much power from the engine.

 

The factory Turbo Buick/Olds442/Monte Carlo SS converter was rated 2600-2800 (depends on who you ask). There is no way GM would have used a converter that loose if it would cause customer complaints or drivability issues. Once the converter is locked, there is no slippage anyway. Go with the looser converter, you won’t regret it.

Btw, converters are input torque sensitive. At maximum torque, a converter might go to 2800 rpm. But at part throttle, the torque is lower, and so is the stall speed. A good quality converter won’t feel sloppy/mushy crushing around.

 

So I called the guy, he's at $500 and does include the Monte SS torque converter but it wasn't pictured. shall I just go ahead and put it in.just do a filter and fluid change. Or do you think I should put a different converter in. I'll get in the car but I'm not going to beat the crap out of it or drag race it,it's more of a weekend cruising car.

 

I would do a filter, gasket fluid change yes. I would run that converter. That being said I just added a 3000 stall to my SUV with a 450 hp 5.3 and it sure helped it get off the line faster!

 

Is the torque converter bolt pattern the same between the chevy and Buick flexplate?

 

im not 100% on that but I believe so.

 

Neat - thanks!

 

How did you set up your lock up? Does it need 12V? How did you get the 10 sec delay?

 

I have Ign 12v through the brake switch to the TCI vacuum switch. That feeds a cheap module I bought on ebay that is a variable delay. That runs to the 12v feed on the converter lockup plug.

When vacuum drops, it unlocks. When I brake, it unlocks. If it shifts into 4th gear, 10sec later it locks.

It isn't perfect but it avoids some harshness with the 4th and immediately locking up.

I think I'm going to rewire it to work off the ground side of the trans lockup switch.

 

Lots of options for how to hooked the lockup but in the end be sure to hookup a brake switch in line so you don’t stall the engine when you do a panic stop. I almost crashed my 91 gmc when I had to slam the brakes to avoid a collision. I had a toggle switch to control the lockup but no brake switch.

 

Buick 350 - under 500HP w/3.42 rear - Yes, buy it.
Yes, change filter and fluid.
Regarding the TC stall, due to cam, yes just buy a 2800 It will be fine, but try the TC that comes with the trans first to figure things out.

 

Got it yesterday, is the front plate normally that clean again he claimed 56,000 miles. Found most of my parts on COBRAtransmission.com anybody here dealt with them? Now I got to find time to pull out the old one and get this one in

 

Thoughts on trans filters, one the left is Bowler perf. the one on the right is from cobra trans. Outside looks similar/same. It's the filter material difference, Bowlers is a plastic fine screen, kinda like prefilter material. The Cobra filter looks like a yellow fiber/paper? I ordered one from Cobra transmission by mistake the bowler kit came with a filter and Gasket and it seems like the same material inside as the one I pulled out. Here's the kit I ordered
https://shop.bowlertransmissions.co...es/products/bowler-200-4r-lock-control-module