The Holley 1904 was prone to warpage of the main casting and the bowl, similar to the Rochester B. Since the bowl mounts vertically on to the main body on the 1904, warpage causes a fuel leak at the bottom of the bowl.
The earliest 1904's had the problem, but it took longer as the bowl was glass, which didn't warp. When the glass bowls were replaced with die-cast bowls approximately 1959 or so, the problem got worse, as the die-cast bowls also warped.
Hope the clone addressed this issue.
Some 30 or so years ago, the 1904 with the glass bowl was popular with inline 6 hot rodders and multiple carbs, as one could actually see the fuel run into the bowl and the float operate. Because of the leakage, less popular today.
Jon.
