Head unit install queston

['68OrangeSunshine]

Back in the old days we used about 5 or 6 inches or "plumbers tape". Not really a tape but mild steel [about 1/2" wide] with perforations every 3/4 of an inch. It comes in short rolls. A length of that goes from a bolt on the firewall up to a stud on the back of the radio set. It's used to lessen the strain on the 2 knobs, Tune and Volume, that secure to the 2 holes in the front of the dash...