That is definitely not a stock pedal assembly.  Stock has an angled pedal pad and a rod that goes up thru the grommet under your mounting plate.  The pad is hinged against the rod and yours looks solid.  If so, you may have some difficulty mounting a stock one.

Mustangs Plus has photos of the assembly and parts under Engine Parts.

Ok, I don't think I was clear....

I know this is not THE stock mustang gas pedal.  I believe it is some universal pedal purchased as a replacement FOR the the stock mustang pedal.  I want to know the exact manufacturer p/n so I can modify the pedal assembly and just change the pad myself.  I'll figure out the engineering on my own.

I'm trying to identify this exact pedal assembly so I can buy a duplicate and hack at it and take measurements to change out just the pad.  I don't want to pull out the existing pedal or change out the whole assembly.  Everything is already wired and positioned to fit this one.  So long as I can just find a way to swap out the pad it will look nice.

I've been doing image searches and this far no dice.  

TremendousWand wrote:

****read comment below.  I know this is not a stock pedal assy.  I'm trying to find the manufactuer p/n of this pedal assy so I can buy a duplicate to re-engineer to change out the pad to the '66 style gas pedal.*****

This is the pedal currently installed on my 66.  Looks like it's a universal pedal assembly for fox body mustangs but I can't find it anywhere.

I want to take the pad off and fit a stock pad to complete the look.  But I wanted to buy a new pedal assy to modify and fit rather than pulling the old one off.  

Anyone have any clue who the manufacturer might be or where one like this can be found?  Thanks

 
Have you taken the pedal assembly out and see if there are any numbers on firewall bracket, pivot arm, or back side of pedal?

Any numbers/letters/symbols may help identify what it came from.
Did pedal come with the car?
Previous owner?
Just some ideas.