1980 Datsun 210 stock tire size?

Both my mother and I had 1980 Datsun 210 Hatchbacks. Mine was the low end model and came with Toyo P155/80 R13's. Actually these were cheap bias ply tires and only lasted about 10,000 miles. My mother had the "sport" model and it came with Bridgestone P175/70 R13 radials which lasted a lot longer.