What size tire using 15x6 wheel?

This is the thread I looked through, not every page, need to find a 15" Cragar: Show your 5x4 small bolt pattern wheels!

In my case, 14" wheels, the taller/wider tire fits better, especially at the front bottom corner of the fender.
The backspace is perfect.

The same size wheel, smaller tire, smaller backspace, it's closer to the front corner, to the point that I'm not convinced a 215/70/14 would clear on this wheel.

I think the bigger backspace is the way to go, even if it means a wider wheel.

This makes sense to me: How to calculate tire size?

So that's where I'm at, and that's basically undecided. I was going to get new 15" Cragars all around, but got a set of sbp steelies for the rear, bought a set of steelies for the front but they have the same smaller offset.

I use this or similar site to check tire sizes and get a visual, although the visuals may not be exact, it helps.
Tire Size Calculator