15x8 w/3.75" backspace question

What size tire?

3.75 isn’t the best backspace for a stock A-body rear with large bolt axles with thicker axle flanges. Especially with 15x8 rims.

Is the rear end jacked up at all?

at stock height, 4.25” rear backspace on a 15x7 with 245/60/15

275/60/15 on a 15x8 with 4.5” backspace. Might need thin spacers to center perfectly