Hey Johnny. I don't know if it helps you out but back when I needed springs for a motorcycle shock, the circle track people came to the rescue. I realize that a motorcycle is much less weight that a Maverick but most rear street bike suspension is ran through a linkage that acts like a lever on the shock so it needs a much higher rate than if it was just bolted to the frame from the swingarm. Places like Eibach, Tru Coil, , AFCO others have catalogs full of springs of whatever length, diameter and rate you could ever ask for. Worth look and would probably be relatively inexpensive compared to a mustang 2 kit.