[BHolm]

If you have a good charge in the battery it sounds like the starter to me.
Check to see if you can hear the fuel pump kick on when the key is turned forward if you can usually the pump is alright. If the van won't turn over and the fuel pump kicks on then I would start with the starter there is a solenoid on the starter that can go bad.
Don't be surprised if it is the fuel pump our the starter those are probably the main to problems with Chevy vehicles.