I have a 1990 GT that I got recently.this is my first mustang.its hitting the rev limiter at 4900 rpm.that seems low.how do I change that? It doesn't have a msd ignition box but it does have a bama tune. I called them and they said that the rev limiter was not changed with the tune as far as they know. do I have to take it to a performance shop? Or is this something I can do by myself? Any help would be greatly appreciated thanks.