Need the Brethrens help on some pork butts

Well, a private club I'm head trustee of has its annual picnic Saturday. I'm doing the pork butts which caused a little trouble with another member who self volunteered himself "his plan high heat and done in 5 hours" the member who donated the meat said not a chance and it's back to me doing them. I think I've got it down but I usually don't cook that much and don't want to screw it up. And I know the other member will be running his mouth, so I DON'T want to screw it up!! I want to make sure no matter how much he runs his mouth the pork speaks on its own.
My plan is to inject them with the Chris Lilly's injection recipe "did it before and turned out good" rub them down with mustard and then Lilly's rub recipe. And smoke with Hickory or Apple I can't decide. My question is we plan on eating around noon on Saturday. What time do you think I will need to put them on Friday? Its 8 shoulders weighing in at about 62 pounds. I originally thought about 10:00 pm Friday which would give me about 12 hours. I have an hour drive there and then set up. However I'm now thinking 8:00p.m. to allow a couple more hours. I'm cooking at between 225 and 260 degrees. Do you think I'm allowing enough time? I don't want to be sitting there at 11:00 with them not done! I know last time I did a bunch after 4 hours they were still so hot out of the cooler it burnt your fingers pulling them. So I guess early is better than late! Anyhow any advice would be appreciated. Just don't want to give the other guy anything to talk about : )
Thanks
David

Well my cooker is actually a dreaded gasser : ( but it works well. Heres a pic

Thanks for the help everyone. I was a little worried at the start, 62 pounds of Pork Shoulder about maxed out my smoker had one more empty shelf but did not have the height needed to fit the shoulders. I did finally manage to arrange all 8 shoulders. I put them on at 9:00 p.m. stayed up most the night checking on temperature and wood. It stayed about a perfect 250 all night. I pulled all 8 at 8:00 a.m. at 195 degrees. A couple of the smaller butts got a little higher than I'd like but they were still alright. Unfortunately I did not get any photos, didn't think about it till too late. I double foil wrapped them all and into the cooler with a towel covering them. Got to the club at 11:00 and started pulling. So hot I had to wear gloves. I pulled 3 and the picnic started at 1:30. With all the food we had "Burgers, Bratts, Polish sausage, Hotdogs" they barely ate the first 3 I pulled. Had 5 whole shoulders left over. I pulled all 5 of them at 6:00p.m. and they were still hot enough to burn your fingers! But I have a lot of pork to vaccum seal for our next event! Had lots of compliments on the pork and lots of requests for left overs to go!