Well...you see that 11ft lbs was one FSM year. 13ft lbs is another I've seen. The 11ft lbs was originally for the plastic LIM gasket w/o metal sleeves. The 13ft lbs I believe was the metal sleeved version. Me, I figure there's a tsb that I didn't look up that would tell me to use 15ft lbs on the aluminuns and have never had an issue. However the bigger thing here is...I've never had one loosen on it's own. Leak yes..loosen no.
So add the sealant/locktite and either of those should keep it from leaking.
