Wheel and tire fitment 65 Barracuda

Or I was thinking of these … View attachment 1716319782
They are 15x7. 3.75 backspacing and for the rear of the car. I have nice 14x 4.5 steelies that would be for the front. I’d paint them either black or body color. The pic above is a new wheel. Thoughts?
Possibly not enough backspace. @66340SEDAN do you know what difference the rear wheel openings are from Valiant?