Normal wear and tear. U-joints, starter all the things that you would expect to go wrong with a vehicle this age.
Truck is a beast, has lots of rust, but that adds character.
I agree with the rust it does, I have a 83 also and I love it to death! Also the 450 hp corvette 350 also adds character. There is so much rust on my truck it can cover an entire one of those japanese fart machines.