1968 Dodge Phoenix Covertible

The Dodge Phoenix seems to be what they called the Plymouth Fury in Australia.

Suggest you contact the Chrysler Owners Club of Queensland:

They have a member's web page listing their cars. Several list the Phoenix.

Here is a tire-size convertor for old cars:

This might also help:

The 1968 Plymouth Fury / Dodge Phoenix probably came with 14" wheels and a 78 series tire. The original tire was probably specified as X78-14, where X is a letter from A to J and indicates the over-all diameter of the tire mounted to the wheel. Since the Fury wasn't a small car, the letter size was probably E, F or G. The modern radial equivalent would be 205/75-14 or 225/75-14.

See here for more info:

Any good tyre store. Assuming you have 14" wheels, the original size was G78-14, which convertes to P215/75R14 in today's tyre sizing system.

DS