Do I need to change the lengh of the endlinks after installing
Pro-Kit springs and Bilstein shocks for lowered cars?If I do how do I figure out how much shorter or longer I need to get?

 

As for an exact measurement I'm not sure. But I do know from personal experience that shortening the end links is a good idea for lowered cars as I went through four sway bar brackets before I figired it out. The main thing to remember is to keep the ends of the sway bar as close as parallel to the mount brackets as possible. I don't mean exactly but close enough as to not stress the brackets. I figured out that the angle the end links were at was putting quite a strain on the brackets during driving and after some time they would break either on the drivers or passenger side.