Jocko's, The Hitching Post and Far Western Tavern cook over coals, not raging fires. But, the coals are hot and when you flip the meat, you get dramatic flares of flames. They do this on purpose. If you ever see the owner's of Far Western Tavern cook at their ranch, they do not get the huge flames, nor do the guys doing Santa Maria the true old school way.
Fill you fire box to the top, light the wood and burn it down to coals, them put some logs around the edge, and cook some meat in the center, over the coals. In the restaurants, they cook very hot and fast, as that works best for that style of cooking. You also might consider that you want to have a fire grate built, so that the coals do not sit on the bottom of your fire box. The cooker will last longer, and the fire will burn easier.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"perhaps...but then again...maybe not..."