Hey Judge. I’ve never injected before, only brined, so no experience with that. All butts have a mind of their own so cooking time should be based on each individual. I consistently see around two hours per pound, cooking at 225, regardless of brining or not. With the double load in the #2 I’m not surprised it took longer than that. I’ve only done two butts at the same time (in my #2) once, approximately the same size as yours, and recall it taking 18+ hours.