Ok, so I was cruising by one of those mobile radar stations that tell you how fast you are going. I had cruise set at 55, but the machine said I was doing 48. I do have 17 inch rims with low profile tires, but I matched them up so the overall diameter of them is very nearly equal to the stock wheels and tires. Also, I did disassemble my gauge cluster to do the LED conversion, if that might disrupt the calibration of the speedometer.
My question is this: Is there a way to make my speedometer read correctly again? I went to a calibration shop today, and it turns out the mobile radar station was right. It's about 6 mph off where it should be. The guy said since the car is so new (2002), there is no way they can correct the cluster to read correctly. He said there isn't anything on the market that can help me. His final analysis is that I have to just mentally know that my speedometer reads 5mph faster than what I am really traveling.