how long for on the smoker for 13.4 LB porchetta

[chrisdb]

Made this before but never this big
dimensions are 12" x 6" x7" and it weighs over 13 LB
I basically doubled this recipe
http://www.philly.com/philly/food/restaurants/recipes/135603598.html
I'm thinking one hour per LB ( 13 hours) as a ballpark estimate, and am on the fence about using his Hi/Low cooking strategy as I do most my pork shoulders low and slow all the way through.. 225 - 250 F .

 

[chrisdb]

Been thinking about this a bit.... the Hi/Lo could actually be helpful. To the let the meat rest and on the table by about 7 I need to have it cooking by 5 AM.
I'm thinking of starting it in my oven at 350F for 2-3 hours and finishing it in the smoker for 10 hours at 250F