Expected RPM torque converter and governor specs for passenger car transmissions?

Factory stalls can be as low as 1500 and as high as 2450 for an SBM, and up to 400 higher with bigger engines. The stall all depends on the torque going into the convertor, and the resistance to the driveshaft turning, at the other end.
Same goes for governor-commanded upshifts, and KD-commanded downshifts. These are all over the map, and very much depend on the rear gears installed.. But these are parameters we can change in the Field; whereas, if you pick the wrong convertor, the choices are;
to change it, to change the engine output, or live with it.

Here's a tip
Never buy a used factory convertor, based on what the factory spec is, unless you have a factory-spec engine. Cuz chances are that if your engine has less or more torque than the factory engine, it will not stall where you expect it to.
The very same factory convertor, can stall at many different rpms, in a modest window, depending on what engine is in front of it.
IMO
Torque convertors should not be rated as to rpm.
Rather, they should be rated as to input torque, with a locked output, cuz that's how we want them to work.