It's your car so obviously you will do with it as you please, but why would you want to change something like that? Besides, you'll have to have your speedo recalibrated to accept the bigger circumference to give you an accurate reading.
You'd probably get better responses posting this in the suspension or DeVille forums. This is the Northstar area, but springs don't really involve the N* system. Maybe the moderators will move it for you, maybe not. Either way, hope you find what you're looking for.