So, I must be getting old, because driving around in my car that has turndowns right after the mufflers is starting to be less enjoyable. I am ready to put tailpipes on the car, and I wanted to know if anyone had any real world test results comparing 2 1/2" and 3" tailpipes? The head pipes and mufflers on the car now are 3", and they will be staying the same. I remember reading somewhere that once the exhaust gasses have cooled down, the exhaust pipe size can decrease without any horsepower loss. I would love to use 2 1/2" tailpipes, because they will be much easier to fit on the car, but I don't want to give up anything performance wise. The car is a 67 B-body with around 600 flywheel horsepower. I have a electric fuel pump, fuel filter, and braided lines coming from the gas tank sump all taking up room under the back of the car, so space is at a premium back there. Any input would be greatly appreciated!