What does the red stripe that runs along the inside of the grill represent
Are you talking about '72 to '74 Barracudas? Those are the only Barracudas that have red in the grille besides the painted grilles in '71.
I always thought it looks like the gums around the teeth on a shark or fish.
The 1970 cars that had the red stripe were 'CUDAs only... no Barracudas