Just got this truck from my mother in law who drove it after my father in law passed. It runs well but could run better. The internals at least I can see through the fill hole look clean. Brakes need to be flushed and the power steering as well. My first change will restore and protect for at least 4 oil changes. It doesn’t burn any oil from the last time I checked it. Differential will get 75W140 and lsd additive. Plugs were done a few years ago. Anything else to look for? Running a bottle of redline SL1 as well.