Do you have a picture of the original spring or could someone provide a picture?
You should be replacing with the same original size and shape - my quick search of SA3135 leads me to think it’s a KIF ref 6. But I have no idea which of the three sizes it would be. http://www.ofrei.com/page1438.html
The springs are only as few dollars for a pack of 5. You could always get all three sizes and see which fits.
Good luck.