We tested and developed these parts years ago at XV Motorsports. These were tested on a torsional test rig. At the time, the installation of all the necessary parts resulted in a torsional stiffness rating like a modern car. This eliminated a lot of the creaking/itching associated with these cars. I will say the parts that stiffen the front portion of the car were most important. This included the inner fender bracing, rad support brace and an underhood brace. 2 things that didn't make much difference were torque boxes and boxing the radiator support.