If you want to run a single on the mag-warts start by removing both trebles leaving only one split ring on the belly. Next you can attach a large four-bead chain swivel to that belly split ring. Take the other split ring from the treble you removed and attach it to the trailing end of the bead chain. Now you can take one of those 3/0 Gammies you mentioned and crimp it on to the trailing split ring. The bead chain allows the fish to twist and roll and the single hook often hooks 'em deeper but doesn't pin their mouth shut like double trebles sometimes do resulting in a death-rolling, line-twisting breakoff.

Life is short....Fish hard!!