9" or 10" brake shoes?

I am trying to replace my rear brake hardware but I guess a 1998 comes with either a 9" or 10" setup. I have a Chrysler 8.25 rear axle, so can you tell me what size I need? Is that size just the diameter of the drum? Inside or outside diameter?

Thanks guys!

Burley

The early XJs (through 1989 or maybe 1990) came with 10" rear brake drums. Chrysler changed to 9" in '90 or '91. Your 1998 has 9" drums.