I am not able to find Thermal resistance of op270AZ. Can you share the same (all packages)?
I would like to know about (Absolute)Maximum Output Current Value for Part Stress Analysis.
The OP270 is a very ooooooold part; not recommended for new design.
I would look at using the AD8672.
There is no current limit for the OP270, so it's a function of the output transistors.
I would use 30-40 mA for calculations.