Could have tried rolling them for more space.http://virtualweberbullet.com/ribselect.html
To fit more full-length slabs of ribs in your cooker, try rolling them. Roll each slab into a loose circle, overlapping the ends a bit. Secure the rolled slabs using skewers or kitchen twine, then stand the ribs on edge on the cooking grate. Using this method, you can easily fit four slabs of loin back ribs on each cooking grate. Try this method with spareribs, too.
Bamboo skewers work well for rolled ribs and are very inexpensive. Due to the "low and slow" heat of barbecuing, they don't need to be soaked in water before use. Once inserted through the slab, trim any excess with scissors for easier placement of the slabs in the cooker.
Rolled ribs tend to hold their shape after cooking, so you won't end up with nice flat slabs. If you try to flatten the slab, the meat will usually tear, so just cut the slabs into short sections or individual bones for presentation to your guests.
With rolled ribs, any areas of meat that touch one another during cooking won't have that nice brown color and smoke penetration like the rest of the meat. To avoid this, arrange the ends of each slab on the skewer so they won't touch during cooking, as shown in Picture 1. If you end up with splotchy areas of meat, just apply sauce generously to both sides of the slab and no one will notice the difference.