As we've discussed before in other threads the presence of a white spray stripe indicates that the coil spring did not test within the predetermined minimum necessary for that particular springs specifications. So as as not to waste it and the car not have issues with the way it drove and felt these marked springs were paired up on the line with another with the white stripes and then were installed as a pair on the same car. For the service replacements do you have the part number assigned to them.
I've never seen blue being used on front coil springs for our applications in 67 and unfortunately Ford MPC's don't list springs for 67 Shelby's
But of course if they did we would have to wonder if what they listed was the original springs or simply approved replacements.
- Can share that I do have a car built with just a 4 speed, no AC or Therm, a few weeks before your car that had evidence of a gold & tan stripes but not a blue stripe.
- On a car 67 GT500 speed with no AC or Thermactor built about 400 cars after yours I have the pictures below if it's strip below
Here is a link to an earlier thread on the same subject Likely these will be merged in the near future
https://www.concoursmustang.com/forum/index.php?topic=13078.msg80018#msg80018
