I dont know why but when i look at that truck i think of a good ole IH Travelette....
http://www.chooseyouritem.com/classics/photos/293000/293219.1966.International.1210.Travelette.jpg
http://www.yesterdaystruck.com/trphotos/a151.jpg
Now i would love to drop an IDI in there
Cummins swap That's what I'm thinking