If you are planning to use the factory correct 14 X 5-1/2" "rallye wheels" -
The factory tire would've been F70-14, closest modern equivalent 215/70/14.
225/70/14s would work but are sometimes on the tall side (for an e-body) depending on your ride height (& getting tough to find).
235/60/14s (short) and/or 245/60/14s (wide if on front) are an option depending on your desired look, but I'd use the later 6" wide wheels.