2001 camry intermediate steering shaft

I have the shaft out of the car because I am
replacing the steering rack and I found that the
lower portion was not sliding on the upper portion--
it was stuck. I now have it moving but the upper
shaft only slides to within about 3/4" from the
inside of the lower part then stops (this is US
model). Should it stop, or should it slide freely all
the way through? Second question: can I replace
the US shaft with a Japan shaft? Japan shafts are
cheaper and easier to find...Thanks!