If I remember they're 215/70/14 on the original 14X5 rims.

Just remember you need 8 3/4 shock plates & bigger u-bolts since the 7 1/4 has smaller tubes than the 8 3/4. the Driveshaft needs to be shorter too for the 8 1/4, we used the old one from the Aspen & it fit fine in the Duster.

The pads above are fine.

Just jack it up & let the axle hang & take a pinion angle reading like that...don't move the car & lay the 8 1/4 in on the perches & re-set to that angle & you're good to go.
Center it side to side also.

Butch