Hi Machoguy

I think you can use theoretical installed load to fill data sheet.
Yes if you do not do the manual selection theoretical installed load & sustain load should be almost same.
How this two load become different, I tried my best to explain in my previous post. You can have a relook again.

For particular spring vendor generally supply four different stiffness spring.
Hard stiffness allow less travel, design also quite compact, required less space to place.
Softer spring have less stiffness value, allow more travel, required more space to accommodate it, sometimes more useful to manage nozzle load, But more problematic for dynamic analysis.

If you manually select, you can choose as per your requirement. If ask caesar to select better don't activate the box.


Regards

Habib