I'm sure you will be taking off the cover. Then you can read the stamp on the ring gear to confirm ratio. That is the only way to be sure.
There was no NAPCO rear end. Same as 2WD.
That is the all time worlds record sketchy rear end swap I have ever seen. A coil that seems to do nothing, welded to the tube, on top of leaf springs with welded Ubolts to the tube. I can't look at it.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn