I started by measuring and cutting the relief for the accelerator. It wasn't clear where the top needed to be and, as a result, the opening for the pedal mount ended up a little bigger than desired. This will require some thought as to what to do, if anything.
There also had to be a relief for the e-brake tube.
Once the pad fit the firewall, holes were drilled for the mounting. There were seven holes in the firewall which I assumed were for the mounting clips. The holes for the brake booster mount, the radiator support rod, and the accelerator cable were also drilled.
The radiator support rod holes had a washer placed over them and the outline was put on with a Sharpie. The openings were then cut with a saber saw to clearance for installation of the rod.
The holes in the corners of the accelerator cable opening were connected with cuts.
The brake pedal mount was placed over the bolt holes. The outline was traced with a Sharpie and then cut so the assembly would mount directly on the inside of the firewall.
The seven mounting bolts had their heads tack welded to the inside of the firewall. Then the heads were rosette welded to the outside of the firewall. The rosettes were ground flush so that no indication of the mounting will be seen in the engine compartment.
The brake pedal mount was cut so that it no longer extends one bolt hole too many toward the rear of the car. This will open up space needed for the gauges.
The pad was bolted into place using fender washers and nuts. At final assembly, the bright fender washers will be replaced with flat black fender washers. The mounting bolts will be cut to length. Acorn nuts will finish it off.
I did set the Vintage Air unit back in place. The salesman where I bought it said he might be able to come over and critique the installation location. I think I will take him up on it.
I weighed using a grommet to pass the e-brake cable through the firewall. I decided that since it was on an angle, it probably would cause the grommet to leak at best, pop out at worst. I decided to use a piece of 1/2" steel tube. After a little welding, grinding, and filing, the cable was passed through for a test fit. When final assembly rolls around, a little sealer on the outside of the cable on the last half inch or so before it is fully inserted will assure a weather tight sea.
The removed section of the brace allows for wrench access to the cable. The cable is tucked up neatly under the dash. The kick panel should install OK. The cable may need to be clamped to prevent a rattle. Time will tell.
The cable exits clean and will easily run along the top of the inner fender clamped from the fender to inner fender bolts.
I needed to poke the holes in the firewall for the items I have on hand before the firewall pad is fitted. I decided to start with the hood release.
I didn't want the cable hanging low in the passenger compartment. I knew the cable had to run high and to the outside. The hood hinge and spring assembly were installed to check for a good spot. Originally, the side of the cowl looked promising. Installing the spring and hinge put an end to that idea. As luck would have it, almost as if Chevrolet had planned it, the hinge bracket has a half round relief which is perfect for the cable to go through.
On the back side a bracket was in the way. Quick work for the cut off wheel and air saw!