82 3TC liftback "suggestions"

Just bought an 82 corolla Liftback for 300..I am starting the maintenance procedure. I bought the upper gasket kit and also will get the carb. kit. (after I find the correct number) I hear rattling at an idle and suspect the timing chain should be replaced. Sooo....my question would be, While I have the block openned up to this point is there anything else I should do to make it another 200000+ miles "hehehe"
I am going for reliable & economical...not so Fast or Furious. But if there are any Definite modifications I should do at this point. Your suggestions would be helpfull!!! :smile: Thanx a bunch.