Ford Repair: E-350, sterring wheel, accelerator pedal

Question
Hi, My van is shaking when the accelerator pedal is depressed and van isn't under load. Meaning, when the speed of the van matches the max for the amount that the pedal is pushed, the front end shakes. Or simply put, the van is at a steady speed. What could be causing this?

Answer
Hi Jason thanks for asking. this could be many of things.
Is this a vibration in the sterring wheel?(like a wheel shimmy) at waht speed is this shaking present? or does this feel like an engine misfire? get back to me with a lettle bit more info
thanks    Chris P