I don't think you would want to go to the extremes that drag racers do, because a road course is a lot longer than 12.5 seconds so you want more longevity from your motor. IMO 12.7 to 12.8 makes sense for a NA road racer.
2001 SS M6 Arctic White
431 rwhp @ 6400 rpm, 398 rwtq
3083 lb. race weight, TSP 235/240
Rolling on 13" Goodyear slicks all 4 corners
150 mph Club Member Bonneville Salt Flats LSR
2002 Duramax Tow Vehicle
2001 Corvette M6 White