No, its not just a "big block" thing. The "S" code GT500s don't normally have the wrap arounds
I have seen numerous 302 cars with the reinforcements
The late Jim Cowles told me he saw a car that had one reinforced tower and one standard.
Interestingly they were serviced both ways. The shock tower was originally serviced with the frame rail and two side aprons
Im not sure a "C" code could be a GT. I thought it had to be a 4v?