Wow- twistie shocks. Pretty sure that was original cause I've never seen them in the aftermarket (and I used to work in parts in 1992-ish).
I don't know a thing about markings, but I think its covered in Zarzarine's book which I strongly recommend for the GTO. : https://www.amazon.com/Pontiac-Resto...toration+guide
I am astounded that this book now costs hundreds! Get the e-book!
__________________
"If you can’t fly then run, if you can’t run then walk, if you can’t walk then crawl, but whatever you do you have to keep moving forward."
|