Matt is right... additionally, here is a diagram from the FSM:
I have a 2 1/4 ton garage jack and I typically use the "cradle" that is underneath the car center front for the front and before I installed my RSB I used the beam for the rear. Now for the rear I just use the emergency jack points.
Another thing to note is that if you're gonna be using the rails a lot, ya might wanna invest in some adaptors for the garage jack so you don't mess up the rails (which I have already done).
