Does the truck still have its data plate? If so run it to see, and yes pictures would allow people here to give you their expert opinions. 3 leafs is not typical of 3600 (or 3100 for that matter which should be 8/8) chassis which should have 8 in front and 7 in the rear.
http://www.stovebolt.com/techtips/VIN.htm Here is information to decode your VIN neither of the auto versions are working.
