The inner bearing should bottom out against the shoulder on the spindle. Its ID should match the straight part of the spindle (inner thicker cylinder). At that point, I am guessing the outer bearing cone should just touch the outer shoulder (where taper starts), since otherwise its rollers wouldn't be tight. It seems that is handled by the parts dimensions. According to the schematic, the dust shield is also important to keep brake dust away from the seal, so don't toss it. Disk brakes were rare in the slab years (my 1965 has drums), and used a bolt-on rotor (like Kelsey-Hayes in A-bodies and Mustangs). I hope your hub isn't ruined (race spun), since it would be very hard to source another. 1970's cars used an integral rotor-hub (at least in A-body), so you get a new hub with every rotor. Since parts interfered, some part is wrong or damaged.