My barrel measurements are H 33 1/2 by 71 around the barrel. Inside of the barrel is 22.5 it's a 55 gal barrel I was told. Now I have the grill grate at 7 1/2 from the top and the intake valves 2 inches from the bottom. I'm using a weber 22.5 charcoal grate as a coal holder and it 10 inches tall, now my problem is that my grate is not 24 in from the coals it's about 20. Is this okay or will I have to install some type of water pan.