Vintage Mustangs are unibody cars which means that they don’t have a full frame - on the track, the bodies of these old cars can flex a lot. I purchased Global West tubular subframe connectors which run down the middle of the car under the floorpan and connect the front and rear chassis rails. To prevent wheel hop, I sourced traction bars as used on the early Shelby Mustangs. Both the subframe connectors and traction bars are tacked in place when the car is on the ground and then the car is raised on stands for final welding.