Blazers are the same as the trucks up front and you can our standard upper mounting plate, RE7 airbags, and a lower cup as shown below. You can also install a set of drop spindles to help the truck get down even lower.
In the rear you can choose from several different options. We do make a notch for the 67-72 trucks that is contoured to match the bends in the frame. We also offer a weld-on parallel or trianulated 4 link kits that you could use and you can run the bags off the axle. Or you can buy our 73-87 cantilever attachment and weld it onto the rear frame rails. The cantilever system would locate the shocks and bags for you and allow upto 12 inches of travel. Here's some images of a Blazer I did with some of the components listed above.
All the products that I was refering to can also be seen on our website,
http://www.kpcomponents.com