Each and every Fox-body Mustang must be checked for torque-box issues. The torque box, shown here, is the main mounting location for the two upper control arms. In cars with a lot of horsepower, or ones that have seen a lot of abuse, these torque boxes can tear out from the chassis. As you can imagine, this can cause major problems, especially if the issue isn't addressed early on. If you happen to have a torque-box issue, there are aftermarket solutions available depending on the severity of the problem and your end goal, or you can re-weld them yourself, if you can assure they end up in the original location.