I had one of these 67s back in high school in 74. We used to peel out for a city block every day at lunch. Extremely fast ride! Oh the stories I could tell you.
My Dad had one of these in same colour blue with white interior. I loved this car. We live in Canada and up here the car was called a "Grande Parisienne" instead of a Gran Prix.
Wow. Love 67 Grand Prixs. Actually love all 60s and early 70s, sexy lines , powerful comfortable. Fast. Also love Rivieras for the same reasons. The pinnacle of american personal luxury. Was lucky enough to have had many and I'm glad I did. They were fun.
My uncle Harvey bought one of these brand new in 1967 - same color even. He was disappointed in 9 year old me when i said that i like Catalina's better ... i liked the stacked headlights on the Catalina/Bonneville and i was only 9 after all :)
I'd massively upgrade the rubber on that car. It can be done in a way that looks period correct. I'd go with P235/55R17, which is what the 2003 Seville wore. You have to change the speedometer cable gearing so you're getting the correct MPH on the speedometer. I'd do that and add a four wheel disc brake upgrade.
I my opinion, THIS WAS THE ORIGINAL 'BAT-MOBILE..THE WHOLE FRONT END WAS UNLIKE ANYTHING ELSE THAT YEAR I THINK GEORGE BARRIS TOOK SOME QUES FROM THIS YEAR GRAN PRIX.