50K miles? You sure you don't want to stick it back where it came from and wake it up in another 20+ years?

That engine is barely broken in compared to how long they can last if oil changed regularly and taken care of. They can easily go to 275K...and some go even farther to 375K+. Not really a ton of things to do and I would follow crvtec90 advise, especially on the timing belts. They are a cheap item to replace and they save a lot of money in case a belt goes into a melt down. They usually last around 60K to 80K and non-interference valves will help from making contact with a piston incase a belt breaks sometime.
Congratulations on keeping low miles on such a older truck. That is a rare thing nowadays.