I'm going to be cooking a 170 pound whole hog for a wedding reception (very informal) I'll be cooking between 250-275 using a meadow creek PR-60 pig roaster. Its the gas model, but will be using the charcoal insert, and plan on using 70-80 pounds of charcoal. About how long will it take the pig to cook?,, I'm thinking 12hrs, how does that sound? THanks in advance for any and all help.