This is harder to answer than many customers realize at first. It depends on how you plan to use your truck. In most cases, the reason for a lift is to make room for larger-than-stock tires. And if you don’t use your rig off-road or in conditions which flex the axles too much, then you can get away with a moderate amount of lift-depending on the tire size you want to mount.
But the problem comes in when your axles articulate, that is when the tires move up into the wheelwells. Then, no matter how much lift you have in your springs, you still can’t force a too-big tire into a too-small wheelwell.
You may need to install bumpstops or a body lift, or modify wheelwells and fenders to keep big tires from doing damage under extreme suspension flex.