phattyduck, you are correct...I may have plugged in an incorrect number. I use a cool site I was turned on to...tiresize.com...it's great for these changes. Gives you an excellent numeric and side-by-side visual comparison of two different sizes, as well as how much it will throw off the speedo. It is an 8.1% increase in diameter, but will still bump the actual speed up by nearly 6mph when I'm looking at 70 on the speedo. I'd really like to correct that.

And to be totally honest, I haven't had the truck long enough to know for sure if it does have ABS or not. Not driving it much with the crappy tires it's now riding on. I'll have to check on the ABS...if it is non-ABS, with the sensor on the tranny, I'm hoping that might be the simplest way to go. In the meantime I will check out that Dakota Digital unit.

Very much appreciate the input, what a great site...