back spacing and sizes

Well based on the rim choices I’m gonna say big bolt pattern, 15” wheels right?

For reference, both BBP and SBP rotors were 10.98” so people will call them 11”. There’s also a larger BBP rotor that also works that’s 11.75”, so saying “large 11” rotors” is misleading. You could make an argument for 3 different rotors with 2 different bolt patterns based on that statement.

Is the 8 3/4 rear from an A-body? Is it running redrilled axles and brakes or has it been swapped to BBP axles with the appropriate BBP brakes? Because that changes the track width.

In the front a 215/65/15 is 26” tall, which is pretty tall and may cause clearance issues on the corners of the fender openings. That will depend a lot on the backspace used in the front, and also on the ride height of the car