How much impact, if at all, will putting larger tires on my truck have on the link between the computer and the motor? Will that increase wear on the motor at all?
Was thinking about going from stock P275/65R18's to 35x12.50R18 123Q E/10 by TOYO with a leveling kit. Will this work?

 

You didn't state what year truck you have, engine size. If you have the 5.4 you will be ok, if you have the 4.6 you MIGHT be asking a little much for that motor with 35" tires. You could get a programmer like Super Chips or and Edge. You tell the programmer what size tires you have and it makes the change in the computer to keep your speedo and odo functioning normally.

 

Going to a taller tire will make the speedometer read slower than you are actually going.