I tried to read this through but how much travel would one need mounting them vert?

Ive the 9 way ranchos still new that came with the monos and caltracks and a pair of Qa1 doubles and they are both 13.5 inches in the body length and if I mounted them on the caltack plates I would have 4.5-5 inches at rest.

Is that enough with the mono springs? Since I looked at the lower mounting kit from jegs the dam things have went up $5 in the last 7 months so if I need them for more room I will get them now.