Can anyone advise what the correct attachment method that was used for the bottom stud on the brake booster on the inside of the firewall. I see there are only 4 red nuts but 5 studs and from what I can see in my disassembly picture and what I removed from the car was a notched washer like used on the bolts for mounting the steering box, and a red speed nut clip, like the green ones used to hold the rear brake drums.