Basicly longer or softer coils for the front will help it drop out, and as for the rear you can fab up some shackles.
If your looking for 4 inches of lift, you can do an add-a-leaf and make 2 inch shackles.
The B2's Rear leaf springs are really tough and can turn inside out without damage (knock on wood). So i would just keep them instead of getting a whole new set of lift leafs