You could use blocks too, for lifting such a small amount. However, the problem is that you'll likely need to change your steering linkage and change the driveshaft/pinion angles as well to get it to steer/handle properly, and not have massive vibrations.
If your truck is fairly stock, you might want to convert to open drive.
On the rear, sure, but you never want to install blocks on the front of a leaf spring suspension system. They cause excessive stress on the springs when used with a steer axle, and are also not legal per the DOT.
