you also seem to have a misconception of what stall speed is
a torque convertor stall speed should match where your car is making the most torque. So say your car is making most of its torque at 3200 rpms, then typically you want a TC with a stall speed of 3200.
The way to test what your stall speed is now is to go from a dead stop and just hammer it, if your looking at your tach you will see it jump to the stall speed of your TQ. <--thats the correct way to determine your stall speed
Stock for stock the TQ has a set stall speed, but in reality once you start making more power your stall speed has actually changed. Some cam makers will actually tell you what your stall speed should be matched with their cam.
But you should never try to see the stall speed by holding down the gas and the brake andseeing where the rpms stop at, thats VERY bad for your tranny <-thats called brake stall and is bad to do for more than a couple seconds
