There you go! Glad you got it fixed.

For me personally, every time I have had a vehicle start riding rough at a certain speed, and then get smooth again at a higher speed, it has been caused by tires that were unbalanced.

Get your tires rotated and balanced (at least the front ones) every 5K miles,

1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.