1. Combine wood chips and enough cold water to cover in a large bowl. Let stand 30 minutes.
2. Rub salt and pepper on pork roast.To barbecue::
3. For gas grill: Punch holes with a knife in the bottom of one small foil pan. Drain wood chips and place 3 cups of the chips in the foil pan; place in one corner of the grill. Place a large 2-inch-deep disposable foil drip pan in center of bottom grate; fill halfway with water. Replace top cooking grate. Close lid and heat burners on Low about 10 minutes. Place meat in center of the cooking grate over the drip pan. Turn one burner off. (For triple burner grill, turn center burner off, as there should be no heat source underneath the drip pan.) For charcoal grill: Close 2 of the 3 bottom vents. Build one pile of 45 to 50 briquettes over the opened vent. Ignite and burn 25 to 30 minutes, until coals are covered with a light coating of gray ash. Drain wood chips. Place a large 2-inch-deep disposable foil drip pan on opposite side of coals on bottom grate. Fill pan halfway up with water (for steam inside the kettle). Place 1 cup of chips over hot coals. Replace top cooking grate. Place meat over drip pan and close lid with opening over meat. Grill pork 4 hours. Add remaining 1 cup drained wood chips to gas grill as needed. Or, replenish briquettes and wood chips as needed every 1 to 1-1/2 hours to maintain a temperature inside the grill of about 225 degrees F to 250 degrees F.
4. Wrap pork tightly in heavy-duty foil; grill 2 hours more, replenishing briquettes (for charcoal) and wood chips as needed, until pork is pull-apart tender.
5. Unwrap pork; cool slightly and shred. Place 1 cup shredded pork on the bottom half of each roll. Drizzle pork with barbecue sauce and top with roll halves. Makes 8 servings.