Well doc... how bad is it?

Well... let me show you. Unfortunately, the rust is not confined to the floor pans. It's infected the various structural members of the car as well. You see, classic convertible Mustangs have several more structural members in the floor area of the car than coupes do. This is to allow for the absence of a roof. These unique structural members are:


Torque Boxes. Structural. These are reinforcement box structures under the toe boards at the base of the firewall that tie the floor to the outer bottom edge of the car (called a "rocker panel") to the firewall (the wall between the engine and the passenger compartments). There is also a smaller torque box at the rear of the car in front of the rear leaf spring mounting point.

Front torque box directly behind front tire.

Front Torque box from the bottom
I'd say I need a new passenger torque box. driver side isn't this bad but I'm going to replace it anyway.

Rocker Panels. Structural. These come in "inner" and "outer" flavors. The rocker panel runs one on each side of the car entirely between the front and rear wheel wells and go beneath the doors. The outer panel is what you'd see painted beneath the door with a chrome trim covering it. The inner panel is a long box shape that is welded to the outer panel, the floor pan, and the front and rear torque boxes. Coupes don't have inner rocker panels but rather just a long flat plate that closes up the outer rocker panel.

View of the Inner Rocker Panel. Both sides look like this and will need to be replaced. Rust has gone beyond the floor pans and has attacked the inner rocker panels.

Outer rocker panel. Driver and Passenger outer rocker panels are in good condition and won't be replaced.

Lower Seat Reinforcements. Structural. These are box shapes that are welded on the bottom of the car directly below the driver and passenger seats and run between the inner rocker, the tunnel (where the drive line runs under the floor), and the front and rear frame members. Coupes don't possess these reinforcements.

These have a bit of surface rust but are still in good condition. I'll probably replace them to avoid the trouble of cutting these off of the floor pans in one piece.

Floor Pans. Not strictly structural. The floor pans are the areas where the passenger feet sit generally covered by carpet. They run between the rocker panels, the firewall, and the trunk wall.

Seat Platform. Not strictly structural. The rise that supports the driver and passenger seats. Welded to the floor pans.

I'm going to replace the entire floor as one large piece rather than individual floor pan sections. This will replace everything seen here including the tunnel.