I would recommend taking some measurements off the frame and seeing where the body panels line up on each side compared to each other.
I had a blazer a few years back with a similar issue. It looked for the world like there was just a tweaked fender, but not matter what I did I could not make the replacement line up. I ended up needing to pull a subtle bend out of the core support, then loosen everything else (the hood, etc) to bring it all back into alignment.
