Full Throttle Travel?
 

Could it be the "sleeve" on the cable touching the "collar" when you're approaching full throttle ? Maybe you could take a look while someone's in the car pushing the pedal ? This looks like an aftermarket cable, is it ?

If it will go WOT with cable connected at carb, when you pull it all the way back by hand, then yes you may have the lower gas pedal rod bent. Make sure to adjust it when the pedal hits the floor, you are at WOT. You dont want the carb to hit WOT and have a gap between the pedal and the floor, that's how linkages get bent or cables broken.

Good advice TedRamAirII. Too many guys make the mistake of having the carb wide open with the pedal or linkage not fully bottomed. Broken parts follow--especially the throttle cable and carb throttle arm.

Also check to see that you don't have too much padding and carpet under the gas pedal as this will prevent the pedal from going all the way down.

I had to remove my pedal and bend it into shape to get WOT. Hardest part is getting that darn C-clip off.

7 out of 9 of the first Gen birds I worked on needed pedal modifications to obtain full throttle. On one I used bronze bushings at the pivot. Helped take away a lot of slop associated with the plastic one.

The end of the throttle cable that connect to the gas pedal, I place a small lead fishing slip sinker on it to take up a little slop and that worked to open my throttle all the way open.

Hmmm I may have this problem too. I've tested WOT by having the wife sit in the car and press the pedal to the floor but always seems like when I reach in I can still turn the throttle back just a little bit more. I put an aftermarket adjustable cable (another long story) on it and have adjusted it 3 or 4 times. Pedal has always felt a little sloppy too. May have to take it out, replace bushings and see if it needs to be bent.

Is the pedal arm repro'd? The one in my car looks weird, not sure if its just the way the factory made them this way or not but at first glance looks like a piece at the end was remove but looking close also looks like it may have just come that way.

I'll post a pic later.

All the 1st gen birds were made so the carb didn't open all the way up on purpose. Thats why the bird had a HP rating of 335 HP & the GO had a 366 HP rating. Pontiac had a 10 HP rat per lbs rule & they did that so the bird didn't have the bigger HP because of the lesser weight of the bird. All it took was to bend the throttle bracket a bit to correct it & then the bird would have the 366 HP rating because the carb would then open all the way up. But it was done on purpose.