You need to educate yourself on convertors.
To give you an idea, an F150 stalls around 1700RPM.
What you are referring to is flash stall. Meaning under load, mash your foot to the floor, what RPM does it go to.
My car has a 3500 stall. My last car was about 4,000. You feel it go into gear. It will move the car in the driveway at 800RPM idle without giving it any gas. It drives like a normal car around town and down the highway. Whack it to the floor under load and it snaps to 3500 and goes.
In a perfect world the convertor you need is 500RPM over where you make peak torque. When you call a convertor company, (do not buy an off the shelf junk converter from summit etc) they will ask you for the dyno numbers followed by the intended use, gear and weight of the vehicle. Again, that's in a perfect world. My car makes peak torque at 3500 and I run a 3500 convertor.