Stiffen your Mustang’s frame
If you plan on using your stock tires, or have few modifications, the stock frame is fine (with the exception of a convertable - which case subframe connectors are a must have item if you want your doors shutting properly 10 years from now). If you are going to race on slicks, or even drag radials, you better have subframe connectors. Subframe connectors prevent the car from twisting due to the torque of a hard launch. Without them you can cause damage to the alignment of your frame making doors not line up, and even creases in your roof. Welded subframe connectors are preferred because the will not loosen up over time, which diminishes their effectiveness.
A car making serious horsepower and running slicks also requires strengthening of the stock torque boxes. This is one of the weakest areas of the Mustang frame, and will break if you aren’t careful. There are some companies that make bolt on kits to strengthen, but again I would prefer to have them welded.
A roll bar or cage will also help keep the frame nice and straight. If you are running low ET’s, you will have to get one anyway, but they do add a little “meanness” to the car, and could save your life if you roll at high speed.
You’ll notice a difference with them too. The car will feel “tighter” and much more stable.
