PCM swap

[RCKSTR]

I did a search and found nothing. I changed my 2003 PCM for a 2004 PCM because it has the program for my supercharger already installed on it, but now my fuel guage is reading incorrectly. I thought I could change my sending unit to an 04, but the part number is the same 03-07. Anyone know why the guage is reading wrong now, and what I can do to fix it?

Thanks