There is a soft spot in my heart for Diamond Dave restaurants. There used to be one in Quincy, Illinois and another in Keokuk, Iowa. I honestly thought they were completely gone, but low and behold I found one still hanging in there in Iowa. I also found a retro t-shirt, too.
It's the biggest, most-followed 'Food Rule' in my life. I will never eat this particular Beloit restaurant's taco because of a disturbing childhood image.
Drive west on Main St. through downtown Rockford. Once you get past the new Embassy Suites hotel go about another 4 minutes before you get to this gem of a taco shop on the west side of Rockford. Mi Ranchito.