if i was pulling cranks and i am not ,but i have trolled for fish once or twice . i would probably use at least 10 lb test .
lots of stress on long lengths of line and the possibility something other than a crappie that might show up .
not sure much past that point ,but i would bet money there is about 4 zillion videos from the professional crappie folks on this subject .
several of the big name tournaments are drag a bait deals from what i have read and seen .
i think i read its really popular on grenada in the summer maybe ?