Not bad at all. You can't mount the burner that deep in the forge it'll just burn up. Pull it back till just the tip of the flare (whatever you end up with) is just poking into the liner. That burner should handle that volume just fine. Remember the number that counts is the inside volume and shape. Those tanks have been making fine forges with that size burner for a hundred years. I much MUCH prefer using 1" 8lb. ceramic blanket refractory it rolls with fewer wrinkles so there is less disr