AC Delco makes a ready strut for the trailblazer, it’s on Amazon for $190 apiece,I just put in the original skinny front Bilstein struts and rear Bilstein shocks that came on my trailblazer, it had the premium smooth ride ZW7 package from the factory, found them on eBay, had to rent the spring compressor from advanced auto to put the struts in, hardest part was getting the rusted nut off the rod of the old struts.