Hey all I just bought a used 06 Roush. It has all kinds of stuff on it but my question is about the speed. It has 18" roush wheels (275-40-18 tires) up from the stock 235-55-17. It also has 4.10 gears also up from stock obviously. As far as the speedometer issue goes can a ford dealer re-calibrate this or do I have to buy a programmer to do it myself. It also has a ford racing 400 hp tune loaded in the ecm for the whipple sc. this recal wont affect the ecm tune will it????? Any help is appreciated.