I personally agree that those tires look too tall. I think you should go a little shorter in the back, and make the fronts a little shorter than the back.

Personally, for an old car I like to try to find tires with a high aspect ratio, like a 70 or 80 series. That looks more period correct to me.

I find this online tire size calculator helpful, to help visualize what size tire difference I want to see from front to rear.



https://tiresize.com/calculator/