Here's an old ad on FABO that shows the front and back side of the V8 pedal. One is missing the nylon rub pad, other has it.
For Sale: Early A-Body V8 Gas Pedal Valiant Dart Barracuda
And it looks like Detroit Muscle Technologies offers a new reproduction (without the nylon pad?).
Mopar A Body 63-66 Accelerator Gas Pedal (for V8 cars)
To use the V8 pedal, you would also need the 64-66 V8 firewall throttle bracket so you could cut the spoon off it. Or maybe adapt something similar, but I have no idea right off hand what might work.