Give National or another spring manufacturer a call. They can build you just about anything you want. I have personally seen 20" lift packs on an early 80's Chev. You can weigh your whole truck then the front and back on axle scales. Then the springs are made to your usage and payload capacity. A friend had a set made a while back for his superduty, 9" lift with no payload capacity. Rides nice and bags were added over the rear springs for when he throws somthing in the back. Keep in mind when going with lifts over 10" steering becomes more costly to correct and drivelines become an issue, especially with short wheelbase vehicles. Not that it can not be done just costs money to make it right and safe. There are a couple of large lift Chevs runnin around here with no front driveline, guess they ran out of money to do it right. Good luck, have fun and be safe about the mods
