It will bolt in. Driveshaft will have to be shortened? I think there is a tread to use your brake set up on a 3rd gen to fit 16 in wheels. On my phone so can't search for it very easily
If it's only rwabs the most you should need to do is wire up a plug for the new axle. The abs module is only looking for a pulse signal. The other thing is speedo correction, this will need to be accomplished with a smarty etc. If the truck is 4wabs you will need to ditch the abs or find a custom tone ring for the rear axle.
Spring perches are almost the same. Within a half inch. I think Peterson's did a write up about a swap. Josh Roach had a thread that I posted all the part numbers and cost on it. Thread title was "best axle swap"?
Yes it was, but the half ton and 3/4 ton perches are off just a tick also.
Yeah buy a repair plug at the dealer.