we just recently got back into roasting whole hogs,after about 30 year hiatus from it.kinda turned into a job,which sucked.back in the day anyway we had three converted 250 gal.fuel oil tanks cut in half,on wheels,two were rotisserie machines with or without baskets and charcol fired and the other was a flat rack machine and was lp fired.the last three years we've done two or three a year,and we use a friends traeger commercial grill,makes it pretty nice.  anyway the recipe we have been using is pretty simple.the night before we roast we inject the hog carcass with teriaki marinade,and rub the outside with the marinade,then we mix cold smoked sausage cut in 1'' chunks with sauerkraut(about 4 gallons for a 280lb pig)and stuff the cavity with the sausage/ sauerkraut mixture and sew it up with butchers twine,let it set overnight and roast the next day at about 300-350 deg.usually takes about 9 to 11 hours for a 180-210 carcass.  never had to keep any leftovers. the last two years we have even done a small lamb(75-90lbs)seasoned greek style and it has been pretty good.