BigJ

Ok, I installed the program last night, but finally got to put some "good miles" on it today. I'm not sure if it just took awhile for the computer to adjust or what, but this thing kicks ***! I have yet to go full WOT, but I got the chance to do a few 3/4 throttle runs today. Launched like a champ, no spin, just launched, but the best part was the 1-2 shifts... and the truck shoots forward on the shifts now. Last night was just too soon to test it out I guess.
I do need some help though, my speedo is WAY off, it says I'm doing 95 when I'm only going 75 The programmer has 2 options for tire size: stock tire/wheel size, and aftermarket tire/wheel size. You have to put stock sizes in before you can enter aftermarket sizes. Well the stock tire size said 270mm, but the actual stock size was 235mm, so I changed that, and changed the aftermarket size to 275mm. Wheels went from 16" stock to 17" aftermarket. Did I do something wrong? The only other thing that could be the cause was the gear size change. But that is pretty cut and dry. Any thoughts??