low speed front end shake

2013 2500 g56 4x4 the front end shakes terribly when i slow down and hit 20mph to stop. I replaced my tie rod end and drag ling with synergy's hd setup. I have a carli lift going on with track bar, control arms and a synergy steering box brace but i also ave a steering box i need put on. does anyone have any idea what else it might be or if i completely missed? it does it in gear and in neutral