i drug out the 55 gal uds today and thought i would cook some ribs. by the way my uds is a GASSER. before you judge me take a look at it.
i cut the bottom out of a 55gal and moved it up to the first rib of the drum and re-welded. in the 12" space below i attached a 55,000btu turkey burner,it only heats up the underside of the bottom.
i then use the regular size rib-o-lator that fits down inside the drum. if i remember right i drilled the spit rod holes about 7" down from the top and then added a universal motor bracket to the other side. i then use a flat lid to cover it.
they tasted unbelievably good. the smoke wasn't overpowering nor was the seasoning. everything was just right for a rib party in my mouth. that rack was gone in 10min. i ate them all myself. i love my rib-o-lator, it never fails me.