I just replaced the thick spongy gasket that sits in between the bowl and tank and tighten the tanks bolts as tight as i could (without over tightening) and no matter how tight i tighten those bolts, water is still falling from the gap between the bowl and tank. Also, it always falls from the sides and not front or back (or at least that's what it looks like).
This is a 1982 Gerber toilet.
I took the old gasket which was really worn to home depot and got a similar one (which was the black color one from FluidMaster and not the red color one which comes in the FluidMaster toilet to bowl kit).

Any ideas on what I am doing wrong???