1972 318, coolant getting into oil

My used-to-be Olds Cutlass V6 suffered the much publicized GM intake manifold gasket failure. dumped the whole thing (coolant) into the pan one afternoon. I bought the cheapest wally world oil and filters I could find, ran it about 1/2 hour at idle and then changed it, ran it about an hour and changed it again. My former supervisor bought it and it's still doing fine couple years later.