Each engine is its own separate entity. I have found through my dyno tests the there is a literal .3 HP (point three) difference between the yellow, red, silver and blue springs! Hardly enough to worry about.
I also took a customers sled out and tried each spring spring on a radar gun. The lighter blue spring produced the highest MPH. But once again, it was only a difference of .3 to .4 MPH between the yellow and blue springs.
Freddie