I dont want to even say it because you guys are going to call me a BS artist. But My friend said that when he was driving next to me that his speedo said 85 then he slowed down and I kept going. I have stock gearing and he has a digital dash. I felt great when the told me. There were 4 people in the truck who all said the same. Maybe Ford doesnt know how to cal a speedo. Anyway after the port and the carb change I think its slower but a hell of alot quicker. If you know what Im sayin.