Pick an oil with a high zinc content if you have not cat on a car. Think something like Rotella-T. ZDDP (Zinc DialkylDithioPhosphate)is found in heavier duty oils.

Remember that your engine was designed in the Mid 80s. Oil has changed a lot. Buying what is fancy looking or what the telly says is good might not be for your motor.

I'm currently breaking in an engine on crap oil. Plain old 10w30. When I get this 2.3 Lima engine seated nicely I'll switch to Rotella-T or Delvac. My car has flat tappets. Sure the cossie engine doesn't but remember when it was made and what ZDDP levels were back then.

Or just throw any old oil in there and have at it.