Has anyone done any investigating as to what the racers actually used, if anything, for road racing a '71-'73? I think many people, most people, just add the bar for that bad news, " my car really needs this attitude". I CAN tell you however, that when I used to work at a Mustang restoration shop, I was doing some suspension work on an earlier Mustang/Shelby, and I removed the bar with the wheels on the ground, then lifted the car with the wheels off the ground, and found you can't get it back on. The front end unibody flexes enough to prohibit the bolts lining up . The bar is actually necessary on the earlier cars. I know also that the Boss 302 cars had a reinforcement bar added that connected the lower control arm mounts together under the oil pan as well, for additional rigidity. Our cars have a welded-in heavy crossmember under the pan, which may help in this area, I don't know. Some Trans-Am racer likely has the low-down.