Since you have the 3800, the computer should hold the motor off the redline. The older style motor(86-87) didn't have that "feature" installed, nor did it have a pin to limit how far the speedometer could wind up. Unfortunately, I am not entirely sure how the computer can smoothly limit the speed. My guess is that there is a kind of secondary throttle, or valve, that will close to prevent the amount of air needed to hit the higher RPM from getting in, which would give the plateau effect. They do make racing chips for the computer, however, that won't have the limiting "feature". I have no idea how much they cost, though.