Welcome. The fuel gauge is OK installation-wise. But... it's as reliable as the idiot light. Meaning... that the in-tank fuel level sensor (a float arm, basically) that electrically feeds
both instruments has to be set-up properly ex-factory. This was NOT the case on many or most 2004-05 Rockets, hence this note to you. As Tomo suggests, the fix is known to dealers (but not always volunteered by them

) and easy to perform. But if you get wrong signals, i.e. idiot light "on"
and gauge suggesting an empty tank
way too early, it would simply mean that the fix has not been done on your 2005 issue. And that it needs to be done now.
(certainly hope this does not read as oldtimer's gaga
) Cheers Lorado. Jamie