'68 GTO Front Endura Bumper to Core Support Filler
 

Did all '68 GTO's get this part?
Was it only a/c or HD radiator cars that got them?

Thanks.

Every 68-69 GTO with the Endura bumper had them

Thanks, that's what I thought too. And the sheet metal type hex head screws with the built-in flat washers just simply screwed into the holes in the core support with no clip-nuts used, correct?

Mine has been apart for twenty years so its hard to remember, but the assembly manual does not show any clip nuts.
#14 x 7/8" screw with an integrated 1" washer.

Perfect, thank you!
A good friend of mine recently purchased a 27K mile '68 survivor car with no evidence that it ever had this filler.
The holes in the core support have not been cut by any screws. Must have been a factory oops.