Were rear stablizers stock on a 1969 Mach 1 or did a previous owner add them on? The reason why I ask is I would like to remove them to allow proper clearance for my exhaust. However, I want to make sure that removing them will not cause me problems. I am running a mildly upgraded 351W with a 3.25 posi rear end and an FMX tranny. Thanks in advance.