Retrofit to air suspension or pull and reduce the spacer block height (there is a spacer block between the axle perch and the spring pack). The only downside to that is, you must maintain the driveline angle from the axle pinion shaft to the transmission or you'll have U joint issues. Good news is, you can buy degree shims over the counter or machine the existing spacer blocks and any competent machine shop can do that in a few minutes.
You need to determine the OEM driveshaft angle with the truck unloaded (nothing in the bed, full fuel tanks, with a protractor and duplicate that angle with shortened spacer blocks. pretty simple Geometry actually.
Sounds complicated but it isn't. I lifted my truck (for offroad purposes) and additional 4" front and back and I had to adjust the driveshaft angle (also called the thrust angle), accordingly.