Car vibrates at high speed (over 55) on 2002 Buick Park Avenue

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
Bought new tires last June Had recent balancing,also had front axle replaced.Still vibrates.Car has 157,000 miles.Also was told car has oil leak,needs new upper and lower manifold intake gaskets plus oil sending unit plus valve cover gasket plus oil change plus coolent flush.Right now I just want the vibration to stop.Help
(1) Answer
First thing to do is have the tires rotated and rebalanced and if the vibration goes to the rear that will tell you that one of your front tires was out of balance, Also you said you have one CV shaft (axle) replaced as maybe the other axle is worn and out of balance