My PVC drain shoe sits about 1/8” out of level with respect to the bottom of a new cast iron tub drain opening. Consequently, in order for the rubber gasket to properly seal all the way around, I have to over tighten the flange which results in a slight bulging of the gasket on one side while the other side is just right. No leaks at this point.
Should I be worried enough about this in long term to the point of pulling tub back out, cutting and recementing the shoe? The only way I can think of getting it to be absolutely perfectly level is to fist install the flange/gasket/shoe to the tub and only then build out the rest of the drain trap/overflow/etc from there.
On a separate note, are some of these gaskets better then others? I mean I have one that looks rubber but they all kind of look and feel the same. What should I be looking for specifically?