11" vs 13" rear coil springs

[racinjason29]

What are the differences in running a 13" rear spring vs an 11"? What would make you want to go to a 13" or an 11"?

[MasterSbilt_Racer]

What are the differences in running a 13" rear spring vs an 11"? What would make you want to go to a 13" or an 11"?
There will be no difference in the spring itself as long as you are not over traveling the spring. If, you change the height of the upper spring cup from the ground, to make it work, you have altered the roll resistance of the car.