Instead of having the bolts thread straight into the tank, the new tank has tabs that stick out and the bolts go through the tabs. The grommet you were talking about where the tube penetrates must be sealed somehow now because it's in there tight, not like my old one. Lastly, the gas cap is self venting instead of the scew vent my original had. Apparently there were a few leak sources they had to remedy. Mine was mostly the grommet leak like you had, but I wasn't positive it was the only leak so I just bought the new tank. If you can get away with fixing it the way you did that's definitely the way to go.