‘66 Valiant tire size?

What tire sizes work with the factory wheels? I can’t find the actual specs anywhere online and my car came with 185/70 R13s on it. Being so old, god knows if that’s the correct size or if it just works. I’m looking at going with some nice whitewalls and found some that are 185/80 R13, would those work okay? I know the height and rim size are acceptable, but they’re a different width... what do you think?