Hey, Classic Mustang here in OKC shows a listing for a Fiberglass spoiler and a 'High Impact' plastic. They show the plastic to be for fastbacks and the Boss 351, the fiberglass is listed for 6 cyl and 8 cyl. Any reason to pick one over the other? This will go on a daily driver 71 fastback, not a Mach
Thanks for the help. Scott