You had me worried for a minute! lol I didn't recall anything about the length of the servo saver being any specific distance. So I looked and sure enough the build on page 3 shows the servo saver...but it's a GAP...not a LENGTH per say. I think you were measuring from the wrong spot and I can see in the directions exactly why you might do that. It APPEARS as though it's telling you to measure to the back of the servo saver retainer/nut. I think what I did was measure the gap between that retainer/nut and the bottom of the arms.

I have never had a problem with mine yet and I'm running the stock plastic servo horn. I've got a metal one in reserve, I can't remember if it came with the KIT or with my servo. But I'll switch to it if/when the plastic one breaks.