just for some more info, the bolts were yellow cad 2- I know a lot of you are going to say they were silver- 100% incorrect as I have had 3 original Mustang never molested and 1 was a11K mile Boss 429,
When I took the bolts off the underside were a yellow cad and talking to my platers they were yellow cad and the heat, sunlight, ozone over time took off the yellow cad.
I also over the last 30 years plus and going to the junkyard here in Calif as when I was removing these bolts off hundreds of Mustangs they were about 90% had yellow cad on the underside of bolts.
my 2 cts