adjustable parameters,speedo,return to stock

[gcole10]

After getting the inTune for christmas I had some kinks to get worked out initially to get the correct firmware updated and backup registry uploaded to the device. uploaded my predator tune and was pleased with the results. I have since increased my tire size to 33" tires. I plugged my inTune in to return my truck to stock before taking truck to dealer for regular maintenance and the device said it was successful. Now i notice after comparing my speedo to gps mph that my speedo says i am going 5mph faster than i actually am. I thought bigger tires created the opposite effect. Also, it still seems as though my truck is still shifting firmly with the same power as when tuned. I'm back to reg octane fuel and don't hear knocking of my lifters so i assume the tune is unmarried to the truck?
Also the last time i installed the diablo tune the adjustable parameters feature was inaccessible. Heard of any of this happening before?