This shows the torque increases matches the increase in displacement.

The effect on torque (given equal displacement) between bigger-bore/shorter-stroke and smaller-bore/longer-stroke is not much. The A13 stroke is only 10% longer than A12 stroke. In the old british cars, the stroke was twice as long (or longer) than other cars, hence it had a larger effect.

In racing, in or OEM fleet averages -- where even a small advantage is chased -- it may make a measureable and worthwhile difference.