Got a question rear leaf springs

[bearman]

What's the purpose of the extra holes in the front mounts that the springs bolt onto in the rear I have ss springs.i was thinking if you move them up or down you change spring tension or increase it. Or does it just fit the body up or down.

 

[GTX JOHN]

Changing the front spring mt. location changes your instant
center and affects how the car leaves the line Drag racing. The back spring
hangers mainly affect ride height.
Spring tension is not really an issue.