That year Chrysler should have a 3/4 axle. Center pulls out in the front & it would have a tag on one of the nuts that hold it in place. If not you can pull it out & on the ring gear there is a tooth count so you can do the math. Most of the wagons came with a 2.73 or 3.23. Good looking Wagon.

if you jack up one rear wheel ,rotate it 2 turns while counting the turns of the driveshaft it will give you the gear ratio . will not work if car has a positraction rear end .