new here for 3 days, have learned a lot and look forward to getting my 94 disco fixed up and on the trailes.

 

Welcome. The shop manual set is called the RAVE, and is a free download in links below. With the years of your truck I would advise finding a small indy radiator shop that does construction equipment, etc. They can un-solder the side tank (it is all metal copper and brass), and rod out calcium buildup. Runs about $75 near me. Go back with a 180F thermostat and happy trails. Lots of things to grease underneath; swivels, differentials, transfer case. Part of getting ready for wading is sealing up the ECU box under the hood.