Anybody know what is the size of the springs for a 2000 Jeep Cherokee XJ? I hope I ordered the right ones, I am trying to replace the stock springs. I ordered 17 inch springs. Is this right?

A quick search and the crown springs are 16.5”. That doesn’t account for spring rate though. Likely you will be fine with those as long as the diameter is the same as well.

Is that freestanding height or installed height?

In addition to the diameter, you also need to consider the end design. For instance, the popular Moog 782 pigtail top won't fit stock isolators.

What brand/model did you order?