I'm going up to Lake Willoughby for a couple days and I know the place is known for its lake trout. I'm fishing braid with a fluorocarbon leader, but the question is what pound test do I need? I got some 20lb at the local shop because that's all they had but then went out later and got some 12lb. Which should I use? Does it matter a whole lot or would I have measurably better success with one versus the other. 

Use 12#. The flexibility of the leader will be noticeable. 

What type of lures are you fishing Excuse my lack of knowledge I never lake fish for trout. I would make my decision on based on what will allow my lures to work properly.  Will you be trolling deep, casting etc?

9 hours ago, fishnkamp said:

What type of lures are you fishing Excuse my lack of knowledge I never lake fish for trout. I would make my decision on based on what will allow my lures to work properly.  Will you be trolling deep, casting etc?

I'll be fishing an array of spinners and spoons, as I think trout will key in on them more than anything else. I'll be casting and have to keep everything relatively deep as it's summer, but I guess it all depends where the thermocline is. Lake Willoughby is a glacial lake so it's deep anyways so I think fishing anything over 10 feet would be less than fruitless.