Greetings!
Do not modify the motor, or any part of the operating systems of the vehicle.
Do not let your cousins friends brother work on it.
Make a log book to keep track of the services.
Do not put local coolant in it. Use Nature Spring or equivalent mixed with Preston coolant or its equal. Change at 2 years unless you have an extended type.
Change oil at 5000Km , 10w-30. 10w-40 depending if it is work truck, or just pleasure. Change filter at the same time. DO NOT LET THEM FLUSH THE OIL SYSTEM unless you have a proven problem.
Transmission is Gear oil #90, 2 years, 20000kM.
Differential 2 year 20000Km 75W-80 (GS-5).
Air filter, 2 year, and knock the dust out every month.
Make sure the gas tank is air tight, if not get it fixed. Ethanol in the gasoline will evaporate if not air tight. Try to use Blaze, or other high octane gas.
Do not OVERLOAD!!!
Good luck, and do not trust advice from internet!!!!