Firestone Wide Oval Radial size?

[sector9]

Hi there. I've fallen in love with the Firestone wide oval tyres but I was a bit weary about the bias ply on the rear, radial on the front idea.
I've seen that coker tyre is making the wide oval in a bias look radial.

They don't make the F70-15 size though. The closest is a GR70-15 (overall diameter is larger 27.70 vs 26.90). Any ideas if this will be too much?

Thanks

Tony