I agree with Jonnyk. Its almost impossible to tell you. If some one gave you a number he would only be kinding himself and you. We all agree that you will make more torque with a 2.5 inch exhust over 3.0 inch. for a street car seeing drive duty. I won't even consider putting on a 3 inch exhust untill I know the power plant is making over 450 flywheel horsepower with all of its power adders if any.
