Whats worng with my cargo van? Wont do over 65 miles?

Does the engine race but speed doesn't change .. need more info ,, is the engine running rough?

If engine seems to run fine, you may have lost your top gear in the tranny. You can start by checking condition of tranny, making sure it has proper fluid level. You probably don't have a tachometer in your van to check engine RPM when traveling at 65MPH, so use your best guestimate if engine sounds or feels like it's running at a higher RPM than in the past.

how long have you had this van some cargo vans have a govener on them to limit there top speed such as a u haul