Pattern Length of Railings

[dgraue]

Does anyone know how to adjust the pattern length for railings? I want to edit baluster spacing in the system family guardrail. I go to edit the baluster placement, but the pattern length is set to 4' and is grayed out. I simply would like to change this spacing to 5'. Any ideas?

[beegee]

I don't know why that property would be greyed out - it's not in my metric one.

[dgraue]

Sorry, brain fade on my part. I was trying to select the grayed out pattern length, but that window simply shows the total of the dimensions I SHOULD have been adjusting in the "Dist. from Previous" window.