ok so i just recently bought a tuner for the 00 suburban of mine... i did the 87 tune and changed the tire size,gear ratio, and the shift points(not that much though)

so now i love the tune but when im driving on the highway ive noticed that my truck spedo says im doing like 90mph but i know im not..... any suggestions hints...

OR any tips on how to tune the trucks?(ex: shift points,shift pressure's,)

lemme know your tunes if you have them for superships flashpaq lol