XJ vs. MJ Rear Shackles

I know the rear shackles between the MJ and XJ are different sizes but- are they based on the same format? (Narrower on the frame rail and wider at the leaf springs?)

(This is on my MJ)
Could you re-shackle to the outside of the frame rail connection (it is currently "inside" of the frame brackets?) By eye, it looks as if it is a straight shot from the outside of the frame rail connection to the leaf spring connection.

Thanks- Sorry if my question borders on MODS and has to be moved. :doh:

Someone posted a picture of them side-by-side within the past week or so. They look exactly the same, but the MJ shackle is a tad longer.

yes, from what I understand the MJ shackles are 1" longer than stock XJ shackles