How to Make It
In a bowl, mix the brown sugar with the paprika, chile powder, dry mustard and 2 tablespoons each of salt and pepper; rub the spice mixture all over the pork. Refrigerate the pork, covered, overnight.
Light a grill. Set a drip pan in the center of the grill bottom, and surround with a single layer of lit coals. Place the pork fat side up on the grill over the drip pan. Cover and cook for about 8 hours or until an instant-read thermometer inserted in the thickest part registers 175°. Replenish with a layer of lit coals every hour as needed to maintain a steady temperature of 200° to 250° inside the grill. Transfer the pork to a rimmed baking sheet and cover loosely with foil; let rest for 30 minutes.
In a bowl, whisk the vinegar, mustard, honey and 2 teaspoons of pepper. Pull the pork from the bone in large shreds. Add the pork to the mustard sauce and toss. Season with salt and serve with the buns.