I got my Dad's 1990 GMC K1500 Extended Cab with a 350 and F44 option last year this time and drove it 3,000 miles from Pittsburgh to Phoenix with a mint 1970 Westinghouse console stereo (biggest damn one ever made) wrapped in a tarp in the back. It only had 39k miles on it when I headed back home! Problem was it sat for 4 years unregistered, he was 92 when he passed. Looking back I was lucky to make it all those miles without a problem. Obviously, it needed a new battery to start and a fuel filter to run smoothly. Tires were 30 years old, honestly, so I replaced those before the long trip. It had a misfire and luckly I was able to see a spark jumping from a plug cap to a heat shield and all it took was rotating the cap a couple of degrees to eliminate the misfire. I did a full tune up when I got it home. Then the real fun began; essentially anything that turns needed repairs due to sitting for so long. Power steering pump, water pump, alternator, starter, front differential seals, A/C compressor. It runs fantastic now. I wanted to keep it all original including all the scratches, dents and other marks (he was pretty hard on the exterior). I consider these Dad Patina but the inside was like brand new. I kind a liked the quarky stereo and didn't think it sounded too bad but it had a whine related to engine speed I could not eliminate so I bit the bullet and installed a new 45wpc Sony head unit with four 4x6 Kicker coaxial speakers and two 100wpc powered subs under the front seat. There is no comparison in sound but I kept the old stereo for down the road originality. While I had the interior side panels out (what a *****) to get at the rear speakers I only had to take the front A pillar panels off to get the headliner out. When I left Pittsburgh the headliner was fine but with the windows open and the wind buffeting the headliner it started to droop. Once I had the headliner out I pealed the fabric off which left old deteriorated foam on the fabric and headliner which actual came off very easily. I tried putting the same fabric back on and it looked OK at first but the adhesive wouldn't hold. I found a local guy who only charged $110 including new materials to install new fabric on the headliner and $25/sun visor (they were horrible). Worth every penny!
I really haven't even changed my own oil in the last 35 years (I'm a retired financial controller who worked for car dealers and I always had mechanic friends) but when I was a kid my Dad's vehicles never saw a mechanic and I was number one helper/gopher. He was amazing and there wasn't anything he couldn't do. I guess it started when he was a motor pool sergeant in occupied Korea after WWII. I have amazed myself in what I remember working with him and what I can find on youtube. It has been a blast for me working on my Dad's old truck and it is a great memory of him for me. I hope you have as much fun with your truck and enjoy its uniqueness.