OK went with 35" nitto trail grapplers, wait to install lift very soon, I' think my speedometer is off, My GPS tells me i'm doing 70mph, but my speedometer tells me 65. Putting on larger tires in the past on older trucks would always throw it off but on my 99 it did not throw it off. Am i right on my speedometer being 5 miles off? is there a correction for this. No big deal just wondering. My odometer is right on the money according to the GPS. and its never been very far off before. Anyone experience this?