1968 k10 lift questions

[Dylanic_350]

Hello I was just given a 1968 k10 longbox from my grandpa. I plan on putting a solid lifter 355 in it and retain the 4 speed. My plans are to lift it about 6 to 8 inches and put some military 37's under it. I've been searching and it looks like only skyjacker makes a lift for 67-68 years because of the longer rear springs these pickups have. How would I go upon lifting this pickup? I want to use springs and not through blocks on it. Has anyone lifted these pickups and can you share with me what you did as far as lifts?? The pickup will be driven on the street but mainly used out in the country and mud bogged. Any help will be great!