Another option, if you have the time, money, know how...is a shackle flip kit. I have a six inch lift now. Four inches of block and two in the springs. I plan to get rid of the blocks. A Shackle flip will give you less axle wrap than blocks. Also, it allows for the use of flatter springs which willl give a better ride and a more flexible suspension. Check out
www.offroaddesign.com. They have a kit that will give you four inches in flipping the shackles. Then add another two in the springs for six...so on.