Front End Vibration

Have A 1998 3.0ltr Winstar With Michellin P205/70/r15 Tires Which I Just Had Replaced A Second Time Last Week.the Rotors Are Ford Factory New,new Struts And Rear Shocks[monroe Sensatrac].new Tie Rods.bearings Check Ok.been To Several Mechanics And Told To Just Live With It.the Front End Wants To Hop On You At 60 Mph.starts At About 50mph.took To Diff Balancing Maching And Did Improve.[goodyear].ive Spent Several Hundred Dollars And Little Luck On This.this Van Should Drive Smooth At Highway Speeds.i Do Have 135000 On It But Its In Excellent Condition.except This Vib Problem.any Help Would Appreaciate.

If it is possible, try a set of rims/tires from a van/car you know has no problem (taurus, sable, cougar-tbird 89-95 all have interchangable rims). If it improves then 1 or more of your rims may be out of balance or bent.