You should have the original torquemaster (black or silver) on your engine, thats as long as it was ordered with one, and it has not been swapped out. When looking at the skeg from the rear there is a built in torque tab in the skeg, basically the right side of the skeg bulges out further then the left side, this will verify you have a torquemaster vs. the verado style. All gearcases will be different in relation to exactly how much oil it holds, I have the same as you…. a 2011 torquemaster and my gear case is lucky if it holds 22 oz. Ive spoken with Don at European marine (Which is where the above info came from) about it and he says that some dont hold as much as the capacity says it should and some hold more, said its quite normal. So to answer your question yes allow some oil to drain out, as shown above, once it is full, put the top plug in first, then disconnect the pump, dont be in a rush to install the lower drain plug, grab the new seal and drainplug/bolt and reinstall. I do mine 2x (March/August) per year or 50 hours, whichever occurs first.