How to know if a transmission is broken in?

if i buy a transmission, how long will it take to make sure i can obtain a certain speed.... how can i brake in my trannyHow to know if a transmission is broken in?drive it like you stole it, you don't have to break in a tyrannyHow to know if a transmission is broken in?just be gentle with it and i would say after a 1000 miles have the fluid changed then it should be broken in no big deal