I've found the Haynes Manuals are a lot better than the Chilton's, but they also seem to include a lot of general engine overhaul info that may not be important when trying to just fix a problem. Also, covering years 1981 - 1984 indicates they may have to omit some year specific information.
I've found the manuals I find most useful give info how to diagnose a problem and how to remove and replace the necessary assembly. For instance, some manuals will tell you how to determine if a heater blower motor is bad but give you no idea how to access the motor and remove it from under the dash, which often can be a complicated process. The Dodge factory manual seems to handle this kind of stuff very well.
In my opinion, the 1983 Dodge Ram Van Wagon factory service manual currently listed on eBay for $22.99 plus shipping would be my choice.
karl