I'm to to sure if u can swap diffes from front to rear or rear to front but I'm not sure that is why I am asking like Toyota third members?

 

1st off they need to be matched ratios.
You can swap 79-85 thirds front to rear
A v6 different can be installed in a 4 cylinder application

86-95 IFS front axles won't fit in the rear due to the obvious rrasons