The wheel hop could be coming from your slapper bars. give the slapper some space so the spring takes some of the shock, before the slappers make everything solid. I was reading in the mother mopar chassis book yesterday. And it said that the pinion snubber should be 1/2" from the floor.(stick shift car with SS Springs.) Now here is my theory. If the center of the axle to the end of you slapper bars is 3 X the length of the original Pinion Snubber.....3X1/2 or .5 =1.5" of play before the slapper goes to work! I know you would have to refab them slappers to make it work, but i think you're only asking to twist a axle tube if you don't lets the spring take up some of the shock from the launch. By the way, Nice reaction time!