You've probably figured this out by now, but I'll answer anyway.
Frame on jack stands, tires off and springs out. I had bought the same rs5000x shocks you have. Took the old ones off which were the next shorter size and the axle was bottoming out 2-3" before the new shock. Just looked around until I found what was stopping it.
If anything, these shocks are long for stock mounts as they require about 3" of bump stop. 4" lift would be minimum in my opinion, which is what I have. They'll let the axle droop far enough that most springs will go slack and could unseat if you didn't have bump stop extensions in place. Since that's not really useful travel, mine would be better balanced if I raised the mounts an inch like
@jjvw. But I'm not to the point where even that effort is justified.