Radial tire sizes

[Deleted User]

I am nearing completion of my 47 club coupe restoration and am wondering if someone can cross over a tire size for me? I have 5"x 15" wheels with 4 ply H78-15 polyester tires on them. I want to put radial tires on but don't know the comparable radial tire size.
Thanks,
Chuck

cpr3333

This conversion chart from the Tire Rack indicates that the closest size would be P225/75R15.

http://www.tirerack.com/tires/tiretech/45_conversionchart.html

Do you have an owners manual that specifies tire size? If so, you'll probably get closer to the correct original size using that.

The tires you have may fit but might not be right since letters weren't used for tire sizes until the late 60's or early 70's. Your tires have already gone through one 'equivalent conversion' and converting an already converted size could be adding to the error.