Nissan Repair: I have 91 2.4 engine, 5-speed..., dump 2000, metal fatigue

Question
I have '91 2.4 engine, 5-speed pickup truck, 225000 mileage.  Yesterday it carried 1,500 lbs of sand about 6 miles distance in city stop and go traffic (I did not know "1/2 bucket" of sand weighed 1,500-lbs until now).

Metal fatigue considered, what would be the most likely parts that might have been damaged?

No break-down occurred, but I plan to drive 800 miles roundtrip soon.  I prefer to replace parts  in my city before the trip--where repairs cost less than in "middle of nowhere."  

Answer
heh...........is that all you put in it?.....i reg dump 2000/2500 lbs in mine thru the yrs(66..71..74..81..88..2002)
even carried a 2350 lb cow to slaughter.........really cant think of anything other than make sure you have brakes   safty items........ps.....got caught with 3300 lbs on my 74.