After some bending tweaks to the cable arm, I got everything lined up. I am satisfied with the install, with ONE EXCEPTION:
The pedal rod support bracket that screws into the firewall is plastic. Apparently the OEM part was also plastic? It flexes substantially. My 67 bracket is durable steel, but a different shaft diameter.
I was able to find a metal bracket from Jegs, so when that gets here I will be back at this.
Parts so far:
Pedal assembly
https://www.ebay.com/itm/195232700347
Throttle bracket
https://a.co/d/hECSn4W
Throttle cable
https://a.co/d/2pZAkjI
Metal bracket from Jegs
https://a.co/d/8ffQlgZ