body lift = spacers between frame and body. Usually cheap, but in heights over ~2" or so they can cause problems related to extra stress on teh body mounts. Also can be a pain because you need to address things that mount between body/frame, such as fuel filler, possibly fuel or brake lines, electrical harnesses, steering shaft, fan/fan shroud...
lift blocks = spacers between axle and leaf spring. As you found, only works to lift vehicles with spring-over axle (SOA).
Suspension lift = taller springs, leafs with more arch. CAn be simple for small lifts, but larger lifts you'll need to look at steering geometry and driveshaft angles
Shackle lift = longer shackles. Shackles mount between the leaf spring and chassis, they pivot to allow the leaf spring to flatten/arch as thesuspension cycles. Because its only on one end of the leaf spring, it will only yield about 1/2 the extra height, ie if you get shackles that are 2" longer than stock, it will give only ~1" lift. It will rotate the normal position of the axle, ie the pinion angle will change, should look at driveline angles. If you go too big on the front, rotating the axle like this will cause bad steering (your caster measurment will be out of whack).
Another way to fit larger tires is to simply cut the fenders. I think on a YJ, you can even raise the flares to hide a hack job if necessary.
Now where's those pics of the lift, lowering blocks
