Bought the 700r4 a while back and i know it had like a 2400-2600RPM stall, just don't remember what? Anyway to find out? Also, is it possible to figure out what brand it is?

Probably easiest to look for markings on the torque converter.

you should be able to foot brake your car, and right when you feel the converter lock and begin to "push" the car forward, or your tires spin is where you stall speed is. just because you buy a "2800" stall converter, doesn't mean that is where it stalls at, actually depends on your motor tq output.