swapping shocks around is good idea, i had same prob, with a set of comp-eng single adj, shocks. imo, most ladder bar cars that are close to the sweet spot, seem to hit the tires pretty hard, sometimes a little to hard, if you do not have double adj, and can not stiffen rebound, you can sometimes compensat for this condition by increaseing tire pressure, i would make sure the shock was bad first. if so and you can swing it, go double adj. i have 4 link, they helped me eliminate the hook, unhook condition, poor track conditions also, good luck with test.