hello, I would like to change my stall converter on my th 400 because I put a more powerful engine (sbc 383 stroker of 470 cv). I dismantled my converter but I do not know witch ratio is it? a 1000rpm a 2000? a 2500? no idea do you know how i could know? there is no number on the piece '... the seller advised me to install a 2500-2800 converter but there are so many choices I'm afraid of making a mistake ... anyone have advice? before buying one, I would like to be sure that mine is no longer compatible but I don't know how to check it

 

You call the torque convertor manufacturer and make sure you have the camshaft specs as manf will ask you for them.
You get a hi-stall convertor matching a couple RPM lower than the max torque rpm of engine. Example: get a 3000 stall convertor if engine peak torque is a 3200 RPM.
You will have to add an external oil cooler after the radiator oil cooler and before the trans, generally the top tubing on the radiator tank is return line to trans.
Hook up external cooler, biggest you can get, can never have oil cooled too much, and install per instructions and connect it where the oil fills from the bottom eliminating air from the cooler.

 

Check with the cam manufacturer on what stall they advise you to use.
Here is a simple way to check the stall.

"With the engine running and the brake pedal held firmly with your left foot put the selector in drive and depress the accelerator fully to the floor with your right foot for two to three seconds.
Your stall speed will be the maximum RPM shown on the tach."

 

Ok thx guys 👌👌👍

 

Art Carr Transmissions is one to call .

 

OP

The converter needs to be cut open and the fin angle changed to change the stall speed....IMHO just buy one from a reputable source that is the stall speed you want and has "brazed" fins. Hughes is one company I have used before. IMHO if the car is "primarily" a street car stay on the lower side (2400) vs 3200. If its all about the 1/4 mi than yeah a 3200

What ever one add a external trans cooler. You may even want to install a trans temp gauge...….driving around on a hot day with a heavy foot on the street and seeing the temps hit 240 and higher is better to know that WTF temp vs burning up the trans

My $/02 don't cheap out on the converter

 

Just make sure you have the cam card available when you talk to someone, as mentioned above.