So I got an 81 22R, so what really have I got?

[markjs]

I got an 81 22R, and I hear it is among the most durable engines ever made. Mine runs good, has a slow steady oil leak from what looks like the timing chain cover, and has about 110k original miles on it. I know the 81 was not cursed with the plastic timing chain guides and has a nice double row chain. Anyway, what I am looking for is what are the strengths and weaknesses of this engine. What special maintenance should I pay close attention to outside of oil changes? Basically any info anyone could give me is appreciated.