I'm searching ebay for headers for the 04 GTP and so far everything is coming up as '97-'03, and only fit the monte carlos and regals in '04 and up. What changed in '04 for the GTP? I mean, I know it's a series III engine with the gen 5 M90, but so are the monte and regal I thought? Why would '03 headers not fit an '04? Is it just a matter of the crossover tube, or are there other issues? If it's just the crossover tube, I'm gonna order a set and just modify the crossover.....