The BP doesn't need to be that high. I usually put a shadow plate at the same height as the throat for the first 12''-18'' and put the BP 1'' higher than that. I like the bottom rack 1'' below the center line so that it's at the widest point of the tank. The bottom rack should be between 2''-6'' above the BP, any closer than 2'' and you can restrict air flow and risk cooking the bottom of the meat before the top is done. If you get farther than 6'' away you lose the benefit of the radiant heat from the BP, I prefer the 3''-4.5'' range. In my honest opinion I do not think it is worth all of the extra work and time to modify the BP because the majority of the grease cooks off while the BP is hot and the recess makes it harder to scrape it clean. I mount the BP level from front to back and end to end with a 2'' grease dam on the end and a 2'' drain.