With a sharp knife, cut off the top ½ inch from garlic bulb to expose the ends of the individual cloves. Leaving the garlic bulbs whole, remove any loose papery outer layers.
Fold a 20x18 inch piece of heavy foil in half crosswise. Trim into a 10 inch square. Place garlic bulbs; cut sides up, in center of square. Sprinkle the garlic with basil and rosemary and drizzle with oil.
Bring up opposite edges of foil and seal with a double fold. Fold remaining edges together to completely enclose garlic, leaving space for steam to build.
Grill garlic on the rack of an uncovered grill directly over medium coals about 30 minutes or until garlic feels soft when packet is squeezed, turning garlic occasionally.
Meanwhile, trim fat from steaks. Sprinkle 1 - 2 teaspoons of cracked black pepper and ½ tsp salt evenly over both sides of steaks, rub in with your fingers.
While garlic is grilling, add steaks to grill. Grill to desired doneness, turning once halfway through grilling. For ribeye steaks, allow 11-15 minutes for medium rare, and 14-18 minutes for medium. For sirloin steak, allow 14-18 minutes for medium rare, and 18-22 minutes for medium.
Remove garlic from foil, reserving the oil mixture. Squeeze garlic pulp from each clove onto steaks. Mash pulp slightly with a fork spreading over steaks. Drizzle with the reserved oil mixture.