Recently acquired an 87 4x4 F250 with 460 gas. Real puzzled by looking at a Chilton repair manual. Can't figure out whether this is a light duty or a heavy duty vehicle (no owner's guide came with truck). Has real low mileage, motor strong, so am interested in going over brakes (shot), axles (wiggly), suspension (lack of maint) and hauling stuff around with it. So I've got 3 questions:

1) How the heck do I tell what I've got?
2) What's the best manual for someone who can do most maintenence and repair work when following directions and isn't afraid of it (nice pictures/drawings, good explanations etc)?
3) Where can I find information relating all the id tags (on tranny, differentials, axles etc) to what the components actually are? The tags do not indicate anything but code numbers (for instance the tag says 3.54 dE6Ta JB d610264-2 where it should be either a Dana 44 IFS-HD drive axle or a Dane 50 IFS)?

Pull the rear hub cabs off. If the axle sticks out with 8 bolts on it, it's a full floating axle and is a HD250 if the axle is flush with the wheel, it's a light duty 250 with a semi floating axle. The differential tag is usually acurate showing a 3.54 axle ratio. http://AllData.com has good tech info.