I had the same problem with my 67 and, on top of that, my hinges were starting to crack in a couple places. I bought a set from Willie (Hood Hinge Repair .com) and was very happy with the results. The biggest wear issues that they have is the rivets wear down smaller on the diameter and the rivet holes wear larger which causes binding and misalignment. Willie machines the holes larger and makes his own larger than stock diameter rivets. This brings them back from the dead. He also said he has plenty of NOS Pontiac springs that come with the rebuilt set.
In the meantime, lube the contact and pivot points so that you don't end up ruining your cores like I did. The core charge is not peanuts.