The nut on the bottom of the servo saver determines how much compression is on the spring. This will in turn affect how much force the servo saver will take before 'giving'.
Most people will run the nut with about 4-6mm of threads below it.
Although on the buggy that is a guess, I'm JUST running mine for the first time in a couple weeks. I've run the truggy with this setup in the past and it worked well.
G/L and welcome to the CEN crew!