Wow, I would love to see the expression on the face of whoever pulled parts off that junked truck. It's not the blocks that you need to worry about, it's the U-bolts.
You could either have your front axle modified or you could get custom springs made at a spring shop. There is a guy in california that does nothing but make drop spindle axles, he could probably make a tall one. He advertises in Classic Truck magazine.
Try
www.benzspring.com for getting custom springs, they have good prices and service. They make springs for gunderson and freightliner as well as customs for anything you want.
You could use lift shackles (get them from a 4WD supply) on the front and fix the caster angle with shim stock for a 1-2" lift. Be prepared for some funky handling.
