82 Fisherman fuel tank issue need advice

[SkunkBoat]

If you are just using sheet metal screws and gasket, I would be terrified to ride in that boat. The tank deforms over time with heat/cold expansion. You would need to add a welded reinforced frame around the holes, thick enough to tap threads, so you might as well weld the top shut.

I had a leaking sending unit gasket once. Once a little gas gets in your bilge it runs the length of your boat, you are an explosion waiting to happen.