Almost never done, The Z Crack pines for attention from those who want to plumb some of Tahquitz's hidden gems. It is also a great way to get the blood pumping for the layback of Zeno's Paradox.
The Z Crack is recognized by the distinctive dogleg crack on the left wall of the Maiden Buttress. It starts at about the same height of The Long Climb. Climb up to the small alcove before the right jog in the crack, passing an interesting finger lock or two. Eyeball as much of the crack to come as you can, as the next stretch is pumpy, with glossy feet and hard to read pro. A few tricky rests can be found. Once to the end of this section, pro must be chosen carefully and extended well. Move right around a flake, clipping the upwardly driven pin (offer a prayer to the gods of your choice that whoever of the FA crowd put the thing in wielded a skillful hammer). Do the crux, which involves a long move to somewhat less than solid rock, which eases considerably in a few pulls. Belay where the pitch joins The Illegitimate.
From here either continue to the top on The Illegitimate or Zeno's Paradox.
Finger sizes work well for the crack, with the occasional hand size. The rack will probably be dictated more by what route you'll choose to get to the top.
The pin is really a key piece of gear, as nothing else can be had for quite a while. The pitch should be considered serious, as if the pin pulls, you'll probably get hurt.