Back when I had my Camaro, everyone would run the Silverado filters because they were bigger. Every time I'd go into An autozone or advanced auto, I'd ask for an oil filter for an '04 Silverado with the 6.0 engine. Every time it would turn into the same discussion like you'd have above and they'd insist it wouldn't fit or some other total shit. Finally I went to Napa and asked for a particular filter number, guy said no problem and didn't even look on the computer. When he came back, he asked if I was running it on an LS car or truck. When I said car he smiled and asked if I went "to the other place" first and laughed when I told him yes. Sadly, that guy no longer works there so I just order all my parts online.