Okay, I figure it out. The clip will only fit on the narrow non-threaded end of the gas pedal screw. I had the answer that I was after and didn't even know it. I was going through a four speed linkage container, I saw a complete gas pedal and bell crank assembly that I must have stored away years ago. Low and behold, to my surprise, there was the clip. Amazing. My guess now is the clip is a safety feature to keep the screw from backing out and the gas pedal becoming loose or falling off. It might be considered redundant and or not necessary, but this is an example of "belt and suspenders". What do you think?
I bet most cars are missing this clip and the owners don't even know it.
Take care
Cory