AAL- Add A Leaf, just like the name suggests, you strap more leafs on to get a lift.

Blocks are hard on leafs, because whenever you hit the gas, the tire go forward and the axle wants to twist back(the pinion wants to go over the top of the axle), but it can't because its bolted to the springs, shocks,etc. When you put a block on you axle, you're basicly adding a (in my case a 3") lever onto your axle, so the twisting motion is amplified. It can break springs, but ujoints and drivelines usually go first...or at the same time.. Stay away from them unless budget warrants