If you slow back down to 55 when its shaking you lose the shake and you're good to go till you hit another bump. I replaced the front shocks already and I wondered if anybody had any ideas what it is
Replace inner and outer tie rods with the drag link check 1st . Install a new high quality steering stabilizer and have the wheels balanced with weights on both side of the rims.
My CJ7 use to do the same thing. I installed a gas charged steering stabilizer and it took care of the problem.
Tie rod ends are shot, replace them once you may be able to, I had an 97 dakota that did that and had one break luckily it was only at low speed so when the tie rod broke it didn',t do to much damage.