See thats what confused me too. Everything is stock and original on my 2001 wrangler. If you go to www.autozone.com
you will see they offer to sub-sections, one is a cast with an overall height of 3 1/16" and the other is the composites with an overall height of 3 3/16". But if you look more into those sections, you will see they no longer carry the cast ones, only the composites.
So i called sears auto center to see what they install on jeeps. He said it only says OEM cast replcaement.
So like i said before, when i installed everthing with the composite rotor on without the tire, i can rotate the axle freely. I can put the tire on with the lugs finger tight and still rotate it. However, as soon as i start to torque the lugs down i can no longer move the axle. At first i did both front tires without realizing this and when i put the jeep in drive, it wouldnt move an inch. So i went back and put the old rotors (which really didnt need to be replaced) back on with the new pads. And walla, everything was fine. I could move the axle and the jeep drove fine.
I made some comparison measurements on the new and old rotors. The only areas it was the same was the overall diameter, the bolt hole diameters. Everything else was between .100"-130" THICKER on the new composit rotors. This was even in areas that dont wear down on the rotors.
So I am not sure, i guess i will have to call jeep and ask them their thoughts.