If memory serves me correctly NONE will say "Made in USA" ... they were all made in Canada until the junk started being produced in Mexico. The Canada ones might have been stamped but I think it was just printed - the only purpose being to identify the country of origin for customs as these were produced before the NAFTA agreement.

I don`t think year will be identifiable. They're considered a '68 spring because they're the same as used on the '68 factory SS/A Barracuda's and Darts, hence the 3000# rating. But in reality these are the springs that are suggested for use in race applications even though Direct Connection produced a bunch of others for different weights and manual or auto shift cars.

Don't get visions of sugar plums dancing in your head when it comes to value, they aren't rare. And if they're made in Mexico then they're probably worth scrap money.