Like Don1 says, setup correctly they take a beating. How fast ya gonna go? I know they are good down into 10 second zone. And in the past chevy racers took the 12 bolt out-put the 8 3/4 in. Not sure how long they last in say a 4500 pound racecar with 500 cubes, 700 hp and 538 gears, slicks, 4500 stall and a trans brake launches???