If it has the 6M computer it is speed goverend, pretty low too I think like 115 or 105. I thnk the fix is to use the 5M computer. But something seems funny you should be going alot faster than the governor by the time you hit 5200 in 5th gear. What speed is that around? Does it have the correct size tires? Are you sure its a governor and not the drag limited top speed of the car?