That's another Barris creation(Page 75):( http://www.amazon.com/Barris-Movie-Cars-David-Fetherston/dp/0760301980/ref=sr_1_1?ie=UTF8&s=books&qid=1214567119&sr=8-1 ).
Roughly 1974-76 Dodge Tradesman B-200 or 300.

http://www.imcdb.org/movie_75378-The-Van.html

The picture I have got from trailers, looks the Dodge Tradesman requested in main page. Role unknown. Probably is part of the movie because it is too much customized, but I don't know.