Just the firebox alone - Not to mention the heat it would create, or the toes it would burn, would be a big part of the decision. Gravity water may not meet the HD requirement for H20 pressure. Axles, bearings, floor, frame, and tires would all be items to check on my list.
Rancho To Go BBQ Catering
Spicewine BBQs - West (Left) Coast
Large Spicewine - Ol' Blue
Twitter - @ranchoagogo @ranchotogobbq