How do I tell the difference in torque converters?

[jeryst]

I read in another thread that the torque converters can be different between motors, for example, a 318 and a 360.

My 68 GTS that I bought a few months ago, has a 360 in it. Car was originally a 340. I dont really trust the work that the guy did on the car, and I dont want to wind up ruining my motor or tranny if the wrong converter was used. He said that it has a 3000 stall speed converter in it.

So here are my questions...

1. Would the 340 and 360 converters be different?

2. I never actually looked, but is there an inspection plate where I can see the converter?

3. If I can see the converter, what should I look for to determine if it is the right converter? I read that the 360 converter has external weights, so can I see them easily?

4. If it is an after market converter, would it still have the exernal weights?

5. What else should I do, look for, etc?

Just looking for some answers because the car is getting close to the point where I can take it on the road, and like I said, I dont want to screw things up because I didnt check things out thoroughly.

 

[fishy68]

Yes 340 and 360 converters are different. The 360 is externally balanced so it has a weight (one single weight) welded to the front of it to balance the engine. If it's an aftermarket converter made for a 360 it will have the weight welded on it just like a factory converter. There are exceptions to this rule though such as a neutral balance converter (what is used on 318 and older 340 engines) can be used if a B&M or TCI balance flex plate is used. They have a notch cut out on one side that balances the engine. There is a inspection cover bolted to the front of the trans you can remove (you also have to take the starter off to get it off). Once removed you can have someone roll the engine over by hand while you look at things and see if you see a weight about 1-1/2" long by 1/4" thick welded to the converter. It will be located between 2 of the flexplate bolts. Or you may see the flexplate isn't the stock type and is gold colored and has a notch (half moon) cut out of it. If it has either of these your most likely ok.

Here's a link to a B&M flexplate like I'm talking about

http://www.summitracing.com/parts/BMM-10230/

It's the lower one in the picture.

 

[fishy68]

You might also look for a sticker on the converter as to who made it. A lot of aftermarket converter companies put a sticker on it.

 

[70aarcuda]

since they are called torque converters...

a torque converter behind a 318 might stall at 2000 rpm...and the same torque converter behind a 360 might stall at 2300 rpm...

the 360 makes more torque then the 318 hence the higher stall speed...

alot of 3000 stall converters are 3000 rpm behing 440....but you put it behind a 360..you might be lucky to get 2500 rpm.....440 makes alot more torque then a 360....

that is why they are called torque converters....