Tire sizes on stock rallye wheels.

The Factory Service Manual shows the largest stock size to be an E70-14 on a 5 1/2" rim. w/sway bar and H.D. suspension.

So with a factory rim a 205/70-14 would be the factory equivalent today. The 215/70-14 would probably be the max with no mods to the car. You have very limited clearance on the front because of the cars wider front track.

If you go with an aftermarket wheel the problem would be to get enough positive offset to keep the tire in the fender well.

"Most of the pictures posted here are of cars that are not standard ride height"

tire size coversions from 1960's.jpg

1949 to current tire size conversion.png

tire diameter chart.jpg