Talk:Warframes/@comment-86.111.58.79-20130405201343/@comment-67.166.52.31-20130406072234

The Mods actually work on base stats, so they don't include the per level health and shield you get.

It just so happens that Excalibur has 100 shield and 100 health at base, so you get an extra 200 health and 240 shields.

If you add the mods to a Rhino for example, you'll see a difference.