Detroit Locker for Dana 60 ?

Get a pic with the cover off.

Yes that 225SL29B will work with 4.10's and down.

The carriers are different for 4.10 down and 4.56 up. Series 3 and 5 IIRC. The reason is as the gear ratio number goes up, the pinion diameter gets smaller. The carrier is thicker where the ring gear is mounted on the 4.56 up unit, moving the ring gear closer to the pinion centerline.

If you get the 4.10 down carrier and want 4.56's, you need to run a ring gear spacer.