A/C Accessory bracket hardware question

Does anyone know the lenght of the stud used to mount the a/c accessory brackets on the 86-93 Mustangs?

I have all the other brackets and bolts, but am missing the long stud.

Is it 7/16" thread, 6" or 8" long? Or another lenght?

I just want to go to a hardware store and pick up one....but just need to know what to get.

Thank you, that would be much appreciated