Vehicle shakes when brakes applied/ 1993 olds Bravada

I just replaced both front brake calibers, pads, idle arms and pitman arms but when I apply the brakes the front of the the suv begins to bounce or shake very hard, not side to side more like the front tires seem to bounce. I know my frame is a little bent but I was told by a frame shop that this would not create these actions what do you suggest?