how would you know it isnt stock? i have the numbers on the differential, is there somewhere i can tell? and pulling the axle shaft is alot of work i dont feel like doing now...
I don't know if the 8.25 was ever available on a 2.5L, I'd maybe ask over on www.naxja.org/forum . Wouldn't surprise me if it was, nothing surprises me much anymore with jeep.
You can also contact DC (via www.jeep.com) with you VIN and request a build sheet. They will email it to you and it will list the axle types.