I have read many recipes and posts from the board but have a question
as I seen to be getting some conflicting opinions.

I am going to smoke a 6lbs boston butt on a Weber kettle this weekend.
I want to be able to slice it when I am done, not pulled and chopped.
I am looking to get to an internal temp of about 170 (I would prefer
160 but others are afraid that is too low). I hope to keep the grill
temp between 200 and 250. It will be tough to be more accurate with a
Weber kettle.

Most advice says 45 minutes per pound. For 6 lbs I am looking at three
hours. However, a bunch of what I read says it I should look at some
where around double that time or more.

Is the longer time going to end up in a much higher internal temp and
therefore more suitable for pulling it off the bone and having pulled
pork?

I have no problem waiting till the internal temp is right but I am
trying to plan the finish time so we know when to eat. I don't want to
start too early or too late.