have front end vibration over 50mph any ideas what it might be

More often than not its a wheel/tire balance problem.

Sometimes it is the tire quality itself. Some tires are poorly manufactured and are more out of round than they should be. This makes such tires very difficult to balance and even if they are balanced properly, they will exhibit excessive road force variation due to they egg shape. An example of horrible quality tire: Continental. Absolute junk! Plulled all four of them off my Mazda and threw them away, and know another guy who did the same with his Miata.

Could be bushing on the Universal Joint. Had the same prob w/my 95' B3000 at highway speeds.

I had a driveshaft support bearing bushing problem with my 95 Nissan king cab pickup. The bushing for the bearing was torn and cuased driveshaft vibration, which I perceived as wheel vibration.