After some research, I determined the pedal ratio to be 6.5:1. Not only did this cause excess pedal travel, it should have made the pedal very touchy if I had left it that way. I decided to modify the assembly to achieve an approx. 4.5:1 ratio. Moving the clevis mounting hole down by 7/8" would achieve this.
In order to maintain the alignment of the rod to the booster, I had to move the upper mount up. I thought about cutting the whole channel off the firewall plate, but I decided opening the top would be better. I must admit, I was beginning to think that the smart money would have been to buy a pile of steel and build it from scratch. But I was already on my way, so cut, heat, bend, and drill.
Once I am sure this is the fix, I will weld a section of rectangular tubing to the "ears" created in this mod.
I also had to cut 3/8" off the clevis and a matching amount off the booster rod.
The pedal bracket was bolted back in the car and a hole saw was used to make the push rod hole. The booster was installed, verifying clearance of the new recess. After a frustrating session of trying to set the pedal location and travel, I called it a night.
The sides and bottom of the channel were cut. After some hammer and dolly work, the resulting flap was recessed and the extra was cut off leaving nice gap for welding. After skip welding, grinding, and hammer crushing, the bottom weld was complete. The ends still need to be filled and welded, but that will wait.
I found the pedal pad. Turns out it is a Lokar SG-6008. Anyway, I cut out a cardboard piece to make sure the booster would not hit the throttle cable. Guess what? It did. So I heat and bent the pedal. I also had to drill a mount hole closer to the firewall (not shown in any of the photos). I will weld the support to the square tube cross piece as soon as I am sure I have enough pedal travel. But, before I can mount the booster and check it, I will have to flatten the raised channel in the firewall. The engine comes out the next time I get out to the garage.
I got lucky in that I was able to open up an existing hole to the 1/2" x 5/8" rectangular size required by the throttle cable. Once the cable was attached, the Allstar pedal assembly was put in its approximate location to verify everything is going to fit. The location of the pedal pad is going to drive me nuts until I find it, or buy another one.