We just bought a Toto Ultramax ii toilet that we are hoping/planning to install back-to-back with a non-Toto toilet. We had to get the Toto because we have a banjo countertop and are height restricted. House is 2 bath, back-to-back toilets built on a slab 1987 San Diego, CA. We have no idea what kind of fitting exists in the wall between the two toilets, but assume it was built to whatever code was in 1987. Will we be OK to install the toilet and not have problems? There will never be a time when both toilets are flushed simultaneously. 2nd toilet will likely be an Am Std. We don't want to re-enact that scene from Big Bang Theory when Howard is testing his Space Station toilet with his mother's meatloaf and it ends up on the ceiling. Are we good to go on installing as is, or do we need to return the Toto toilet, rip out the banjo countertop, and get a taller, non-Toto toilet? We really want to keep the Toto toilet, and are time constrained on getting a new toilet installed. Thanks much for your help.