Question for you guys  

We were just talking about this. Back in the 60s modifieds , bugs, or sprints, whatever they might have been called, at Eldora 18 or 19 seconds was a real decent lap depending conditions. Now the street stocks are faster than that. My guess on the increased speed is tire sidewalls. Those old M&H, & double diamonds were so stiff they blurred your vision, and could hold a parked car up even if they were flat.