You could try E-W and see how it works. I was not with the Buck 91 all day so I didn't experiment all that much with E-W, but I figured that if I did it I'd have to use the "tunnel of love" (N-S trench in the coals to allow more air to the back of the box) or maybe short N-S splits on the bottom and E-W for the rest of the load. To figure the usable firebox volume, I measured the width half way back and used that to figure the volume of an equivalent rectangle. The height was about 10" to the cat shield with room for a split higher along the side walls, less than you apparently have but it sounds like the Buck is a little deeper. I could get in 18" splits N-S, leaving a few inches between the wood and the glass. I calculated about 3 cu.ft. usable.The shape and size of the firebox tends to lend itself more towards E/W I think....I have loaded it a few time with the first layer running E/W then everything else N/S.