Mount the curved nymph hook and wrap 12-15 turns of lead wire over the middle of the shank, then push the wraps together and bind them with thread so they cannot spin. This fly is meant to be on the bottom.
Start tan thread and taper the thread over each end of the lead so the underbody has no shoulders.
Wrap the thread back around the bend and catch in a strand of fine mono for the rib.
Dub a fat, loose, slightly scruffy body of tan-grey rabbit forward over the lead, keeping it plumper in the middle than at either end. Loose dubbing is right here — a crane fly larva is a soft translucent grub, not a tidy nymph.
Spiral the mono forward in 6-7 open turns to segment the body, then tie it off and helicopter the excess.
Pick out the dubbing along the flanks with a bodkin so the outline goes fuzzy.
Build a blunt thread head, whip finish and cement.