depends on how old the vehicle is. if your vehicle is over 3 years old, or over 40,000 miles, i'll bet the struts last no more than 6 months before they blow... and the funny part, you probably wont know they're blown until you ride in someone else's car and realize yours bounces like a superball.

also of consideration are the rate of the springs you get on the GC system. a softer spring will tease out more life from your struts.

your best bet is to get a new set of struts so you dont do the labor twice.