I think you would need to replace more than just the grill. I think you would have to have the Rebel bumper as well. I'm going totally off memory but I believe the shape of the Rebel grill (at the bottom) is a different shape as it has a different bumper contour to follow.
Is it just me or does that look like it's designed to fit a regular ram. Looks like the bottom is made to fit a regular bumper.
Just my opinion, but that bugs me. It's like people putting rubicon stickers on a jeep that's not a rubicon.
I know. It's an extreme example