[shaker455]

67' GP's have been in my family since they were new so I can tell you it's rare to see headlight doors open 100% of they're movement.
Maybe post a pic of yours while up to see?
My current 67' GP was in storage for 20 years and the cover did not operate at first.
I had the lower valance off so I could access & lube all the moving parts.
Once I did that I got operation, but it was slow... you had to give it a few mins or start driving while the vacuum increases from engine speed to get them up.
Once I took the vacuum switch apart for clean & lube it now opens as fast as you can walk to the front to look!