You might be able to stuff a 4BT into the van. It's shorter but just as tall as the 5.9. The BT is nearly identical to the 5.9 except it's only a 4 cylinder and with a little searching around you could probably pick one up cheaply out of an old curbside delivery truck. Freightliner put tons of those engines on chassis coupled with Allison transmissions that would easilly adapt to a dodge van. the BT is good for about 190 hp but don't expect neck snapping performance out of it unless you jack with the pump and turbo. They're solid reliable (albiet industrious noisey little beasts) performers and deliver tons of chips and snack foods and uniforms daily :) The nice thing about the bt is it's relationship to the 5.9.. they sound the same when running :) Hope this helps!