If you cant sand the letters off, maybe fill it up smooth over the letters with either resin/fiberglass or bodyfiller/bondo...
Then paint the center, I wouldnt paint the whole thing....
You gotta get rid of the "GMC" on them, but they do look good with the wheels....

 

The letters are actually inside the centers(like under a dark tinted bubble) and the surface of the center is smooth. All I would have to do is scuff up the plastic circle in the center of the cap and spray paint it black. Im pretty sure thats the way Im going to go.

 

Oh, ok, cool...
I thought it was raised lettering, more of a pita to cover up...
Should look good!

 

For anyone else that wants to use GMC caps, they fit without any mods. The only thing I did is put little rubber feet on the four legs inside the cap. The rubber feet are what you would put on the bottom of things to keep them from scatching a delicate surface. Like say a plant pot or stereo component that sits on a polished wood surface. The little rubber feets keep the cap tight when you push the plastic lugs in the caps over the actual wheel lugs. Other than that they fit perfect. They actually take a little work to get off because they hold on so tight.

 

Looking good. Great handy work