Who will know need help ASAP

but on the lock ring there are two tips do they go on each side of the tab of the gas tank or does one of the tips go into the tank tab indentation. I think the more and more I look at it theres a tip on either side of the tab. I just want to make sure because I'm tired of smelling dripping gas. I have replaced the filler gasket, then the sensor then since it had a drip I re-did it again. Now bought a new tank since the old tank has so much dirt in it and changed it out so before putting it back in the car I want to make sure. Is it a good idea to fill with water before mounting and see if there is a drip?