I'm not sure about them making coil spacers that large, but you can use the front springs from a 90's v8 jeep grand cherokee to lift the rear 3 inches. You can also go to 4x4parts.com and order a kit that will come with springs specifically made for the pathfinder that don't require modification like the jeep springs do to lift the rear 3 inches. If you're just wanting the lift to fit larger tires then I would suggest starting with a body lift. Yeah I know body lifts are generally the last route most people want to go, but even with a 3 inch body lift running 33/12.50/15 on stock wheels I still rub the body trim when turning and a body lift gives more clearance for larger tires than a suspension lift of the same amount will. I'm happy with my body lift as the vehicle still rides and drives the same as stock and a body lift on a pathfinder doesn't really look bad like they do on something like a chevy silverado. If you have step rails on the side they pretty much completely cover up the now exposed frame.