ORIGINAL: EARRNHARDT3

Well i took apart the rear diff and it has just the 2 spider gears. So if i read every thing above right i have a Savage 21.
I do have one question can i put the Savage X SS diffs in the 21's bulk heads ( housing that hold the diff/ring gear in to the pinion gear ) Or do i need the X SS 's housings also?

Thanks for the helps Guys

E3