I have a bad front end vibration that occurs at 55 + MPH

Please don't randomly replace parts according to a list. That is by far the most expensive and least effective way of solving a problem.

Start by having the tires checked on a road force balancer. GM has always loved using Uniroyal and B.F. Goodrich tires on their cars, and they are very well-known for developing broken belts. Squirming tire tread will cause an oscillating steering wheel at low speeds and is relatively easy to spot, but there are other ways for belts to shift or break that aren't so obvious. For those who don't know what else to look for, the road force wheel balancer will spot those problems.

You can also try rotating the wheels front-to-back to see if the symptoms change.

A worn engine mount CAN reveal a vibration but it isn't exactly the cause. An area inside an inner cv joint housing on front-wheel-drive cars can become worn, but as long as the rollers keep rolling back and forth in that area, no symptoms will be observed. When one end of the drive train sags due to a broken or worn engine mount, the half shaft angle and length changes. That causes the rollers to move in and out of the worn spot, and causes a shimmy in the steering wheel up to about 35 mph and when under load.

Start by rotating your tires. Look for excess wheel weights on front tires. Does the problem follow the tires to the rear. The rims and tires have to be checked for excessive runout. Ty for using 2carpros