...and on an unrelated note I had to take apart my heads to get a clog out of my left nozzle.
Mission accomplished, however, now when I'm trying to print ABS with it I've got the left nozzle laying down ABS just fine, and the right one dragging across the newly layed plastic, which is then pulling it off the bed. Should I assume this means I tightened the left nozzle a bit too far, loosen it a hair, and re-level? Is there a good way to tell when I've got them at the right offset vs each other?