All of mine have the same base, meaning, they'd all stick out the same amount. I have both Barracuda and Charger caps, they all have the base with #2823339 (probably can't read it in the size of picture I posted, it's the same # I swear).
This is the one on my car, it's off of a Charger, has the "fuel" lettering. The other thing to look at is they need to stick out some, I marked the release lever gap with a red arrow. There has to be a small gap there, otherwise you can't release the cap.