not sure about Toyota warranty, but I know Jeep
Had a 91 wrangler a few years back, installed a 3" suspension lift within the first 10k miles. Had a driveshaft problem at 15k, not covered because of the lift. Had a transmission problem (tail yoke), not covered due to the size of the tires (extra weight), 30k miles, excessive brake noise, not covered due to the weight of the tires/wheels. Went through 2 different dealers for this stuff, asked Jeep corporate, and if the weight of the tires exceeds the specs in the owner's manual, you void the warranty.
Things like AC, electrical, interior will still be covered. Things like engines, tranny, suspension, brakes, steering will most likely be voided due to the lift and the tires you will put on the truck to make the lift look correct. My advice... If you are not doing some hardcore trails, you probably don't need the lift anyway.
You have to really take a look at the things a suspension lift changes (and the extra weight of the tires/wheels), and then weigh the potential consequences. Lifts change the angles for the driveshafts out of the transfer case (u joints, shafts, and yokes affected). Larger tires/wheels add weight (and resistance) to the gears for the tranny, diffs, transfer case, and require more power to stop (more work for the brakes) and require more power to turn (more resistance to the power steering). Also, by changing the wheels/tires, you may lose the tire inflation indicators.
Anyway... Just posting my experience with lifts...